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1 | /* | |
2 | Copyright (C) 2002 Richard Henderson | |
3 | Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. | |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 2 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program; if not, write to the Free Software | |
17 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | #include <linux/export.h> | |
20 | #include <linux/extable.h> | |
21 | #include <linux/moduleloader.h> | |
22 | #include <linux/trace_events.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/kallsyms.h> | |
25 | #include <linux/file.h> | |
26 | #include <linux/fs.h> | |
27 | #include <linux/sysfs.h> | |
28 | #include <linux/kernel.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/vmalloc.h> | |
31 | #include <linux/elf.h> | |
32 | #include <linux/proc_fs.h> | |
33 | #include <linux/security.h> | |
34 | #include <linux/seq_file.h> | |
35 | #include <linux/syscalls.h> | |
36 | #include <linux/fcntl.h> | |
37 | #include <linux/rcupdate.h> | |
38 | #include <linux/capability.h> | |
39 | #include <linux/cpu.h> | |
40 | #include <linux/moduleparam.h> | |
41 | #include <linux/errno.h> | |
42 | #include <linux/err.h> | |
43 | #include <linux/vermagic.h> | |
44 | #include <linux/notifier.h> | |
45 | #include <linux/sched.h> | |
46 | #include <linux/device.h> | |
47 | #include <linux/string.h> | |
48 | #include <linux/mutex.h> | |
49 | #include <linux/rculist.h> | |
50 | #include <linux/uaccess.h> | |
51 | #include <asm/cacheflush.h> | |
52 | #include <linux/set_memory.h> | |
53 | #include <asm/mmu_context.h> | |
54 | #include <linux/license.h> | |
55 | #include <asm/sections.h> | |
56 | #include <linux/tracepoint.h> | |
57 | #include <linux/ftrace.h> | |
58 | #include <linux/livepatch.h> | |
59 | #include <linux/async.h> | |
60 | #include <linux/percpu.h> | |
61 | #include <linux/kmemleak.h> | |
62 | #include <linux/jump_label.h> | |
63 | #include <linux/pfn.h> | |
64 | #include <linux/bsearch.h> | |
65 | #include <linux/dynamic_debug.h> | |
66 | #include <linux/audit.h> | |
67 | #include <uapi/linux/module.h> | |
68 | #include "module-internal.h" | |
69 | ||
70 | #define CREATE_TRACE_POINTS | |
71 | #include <trace/events/module.h> | |
72 | ||
73 | #ifndef ARCH_SHF_SMALL | |
74 | #define ARCH_SHF_SMALL 0 | |
75 | #endif | |
76 | ||
77 | /* | |
78 | * Modules' sections will be aligned on page boundaries | |
79 | * to ensure complete separation of code and data | |
80 | */ | |
81 | # define debug_align(X) ALIGN(X, PAGE_SIZE) | |
82 | ||
83 | /* If this is set, the section belongs in the init part of the module */ | |
84 | #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) | |
85 | ||
86 | /* | |
87 | * Mutex protects: | |
88 | * 1) List of modules (also safely readable with preempt_disable), | |
89 | * 2) module_use links, | |
90 | * 3) module_addr_min/module_addr_max. | |
91 | * (delete and add uses RCU list operations). */ | |
92 | DEFINE_MUTEX(module_mutex); | |
93 | EXPORT_SYMBOL_GPL(module_mutex); | |
94 | static LIST_HEAD(modules); | |
95 | ||
96 | #ifdef CONFIG_MODULES_TREE_LOOKUP | |
97 | ||
98 | /* | |
99 | * Use a latched RB-tree for __module_address(); this allows us to use | |
100 | * RCU-sched lookups of the address from any context. | |
101 | * | |
102 | * This is conditional on PERF_EVENTS || TRACING because those can really hit | |
103 | * __module_address() hard by doing a lot of stack unwinding; potentially from | |
104 | * NMI context. | |
105 | */ | |
106 | ||
107 | static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n) | |
108 | { | |
109 | struct module_layout *layout = container_of(n, struct module_layout, mtn.node); | |
110 | ||
111 | return (unsigned long)layout->base; | |
112 | } | |
113 | ||
114 | static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n) | |
115 | { | |
116 | struct module_layout *layout = container_of(n, struct module_layout, mtn.node); | |
117 | ||
118 | return (unsigned long)layout->size; | |
119 | } | |
120 | ||
121 | static __always_inline bool | |
122 | mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b) | |
123 | { | |
124 | return __mod_tree_val(a) < __mod_tree_val(b); | |
125 | } | |
126 | ||
127 | static __always_inline int | |
128 | mod_tree_comp(void *key, struct latch_tree_node *n) | |
129 | { | |
130 | unsigned long val = (unsigned long)key; | |
131 | unsigned long start, end; | |
132 | ||
133 | start = __mod_tree_val(n); | |
134 | if (val < start) | |
135 | return -1; | |
136 | ||
137 | end = start + __mod_tree_size(n); | |
138 | if (val >= end) | |
139 | return 1; | |
140 | ||
141 | return 0; | |
142 | } | |
143 | ||
144 | static const struct latch_tree_ops mod_tree_ops = { | |
145 | .less = mod_tree_less, | |
146 | .comp = mod_tree_comp, | |
147 | }; | |
148 | ||
149 | static struct mod_tree_root { | |
150 | struct latch_tree_root root; | |
151 | unsigned long addr_min; | |
152 | unsigned long addr_max; | |
153 | } mod_tree __cacheline_aligned = { | |
154 | .addr_min = -1UL, | |
155 | }; | |
156 | ||
157 | #define module_addr_min mod_tree.addr_min | |
158 | #define module_addr_max mod_tree.addr_max | |
159 | ||
160 | static noinline void __mod_tree_insert(struct mod_tree_node *node) | |
161 | { | |
162 | latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops); | |
163 | } | |
164 | ||
165 | static void __mod_tree_remove(struct mod_tree_node *node) | |
166 | { | |
167 | latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops); | |
168 | } | |
169 | ||
170 | /* | |
171 | * These modifications: insert, remove_init and remove; are serialized by the | |
172 | * module_mutex. | |
173 | */ | |
174 | static void mod_tree_insert(struct module *mod) | |
175 | { | |
176 | mod->core_layout.mtn.mod = mod; | |
177 | mod->init_layout.mtn.mod = mod; | |
178 | ||
179 | __mod_tree_insert(&mod->core_layout.mtn); | |
180 | if (mod->init_layout.size) | |
181 | __mod_tree_insert(&mod->init_layout.mtn); | |
182 | } | |
183 | ||
184 | static void mod_tree_remove_init(struct module *mod) | |
185 | { | |
186 | if (mod->init_layout.size) | |
187 | __mod_tree_remove(&mod->init_layout.mtn); | |
188 | } | |
189 | ||
190 | static void mod_tree_remove(struct module *mod) | |
191 | { | |
192 | __mod_tree_remove(&mod->core_layout.mtn); | |
193 | mod_tree_remove_init(mod); | |
194 | } | |
195 | ||
196 | static struct module *mod_find(unsigned long addr) | |
197 | { | |
198 | struct latch_tree_node *ltn; | |
199 | ||
200 | ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops); | |
201 | if (!ltn) | |
202 | return NULL; | |
203 | ||
204 | return container_of(ltn, struct mod_tree_node, node)->mod; | |
205 | } | |
206 | ||
207 | #else /* MODULES_TREE_LOOKUP */ | |
208 | ||
209 | static unsigned long module_addr_min = -1UL, module_addr_max = 0; | |
210 | ||
211 | static void mod_tree_insert(struct module *mod) { } | |
212 | static void mod_tree_remove_init(struct module *mod) { } | |
213 | static void mod_tree_remove(struct module *mod) { } | |
214 | ||
215 | static struct module *mod_find(unsigned long addr) | |
216 | { | |
217 | struct module *mod; | |
218 | ||
219 | list_for_each_entry_rcu(mod, &modules, list) { | |
220 | if (within_module(addr, mod)) | |
221 | return mod; | |
222 | } | |
223 | ||
224 | return NULL; | |
225 | } | |
226 | ||
227 | #endif /* MODULES_TREE_LOOKUP */ | |
228 | ||
229 | /* | |
230 | * Bounds of module text, for speeding up __module_address. | |
231 | * Protected by module_mutex. | |
232 | */ | |
233 | static void __mod_update_bounds(void *base, unsigned int size) | |
234 | { | |
235 | unsigned long min = (unsigned long)base; | |
236 | unsigned long max = min + size; | |
237 | ||
238 | if (min < module_addr_min) | |
239 | module_addr_min = min; | |
240 | if (max > module_addr_max) | |
241 | module_addr_max = max; | |
242 | } | |
243 | ||
244 | static void mod_update_bounds(struct module *mod) | |
245 | { | |
246 | __mod_update_bounds(mod->core_layout.base, mod->core_layout.size); | |
247 | if (mod->init_layout.size) | |
248 | __mod_update_bounds(mod->init_layout.base, mod->init_layout.size); | |
249 | } | |
250 | ||
251 | #ifdef CONFIG_KGDB_KDB | |
252 | struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ | |
253 | #endif /* CONFIG_KGDB_KDB */ | |
254 | ||
255 | static void module_assert_mutex(void) | |
256 | { | |
257 | lockdep_assert_held(&module_mutex); | |
258 | } | |
259 | ||
260 | static void module_assert_mutex_or_preempt(void) | |
261 | { | |
262 | #ifdef CONFIG_LOCKDEP | |
263 | if (unlikely(!debug_locks)) | |
264 | return; | |
265 | ||
266 | WARN_ON_ONCE(!rcu_read_lock_sched_held() && | |
267 | !lockdep_is_held(&module_mutex)); | |
268 | #endif | |
269 | } | |
270 | ||
271 | static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); | |
272 | #ifndef CONFIG_MODULE_SIG_FORCE | |
273 | module_param(sig_enforce, bool_enable_only, 0644); | |
274 | #endif /* !CONFIG_MODULE_SIG_FORCE */ | |
275 | ||
276 | /* | |
277 | * Export sig_enforce kernel cmdline parameter to allow other subsystems rely | |
278 | * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. | |
279 | */ | |
280 | bool is_module_sig_enforced(void) | |
281 | { | |
282 | return sig_enforce; | |
283 | } | |
284 | EXPORT_SYMBOL(is_module_sig_enforced); | |
285 | ||
286 | /* Block module loading/unloading? */ | |
287 | int modules_disabled = 0; | |
288 | core_param(nomodule, modules_disabled, bint, 0); | |
289 | ||
290 | /* Waiting for a module to finish initializing? */ | |
291 | static DECLARE_WAIT_QUEUE_HEAD(module_wq); | |
292 | ||
293 | static BLOCKING_NOTIFIER_HEAD(module_notify_list); | |
294 | ||
295 | int register_module_notifier(struct notifier_block *nb) | |
296 | { | |
297 | return blocking_notifier_chain_register(&module_notify_list, nb); | |
298 | } | |
299 | EXPORT_SYMBOL(register_module_notifier); | |
300 | ||
301 | int unregister_module_notifier(struct notifier_block *nb) | |
302 | { | |
303 | return blocking_notifier_chain_unregister(&module_notify_list, nb); | |
304 | } | |
305 | EXPORT_SYMBOL(unregister_module_notifier); | |
306 | ||
307 | struct load_info { | |
308 | const char *name; | |
309 | Elf_Ehdr *hdr; | |
310 | unsigned long len; | |
311 | Elf_Shdr *sechdrs; | |
312 | char *secstrings, *strtab; | |
313 | unsigned long symoffs, stroffs; | |
314 | struct _ddebug *debug; | |
315 | unsigned int num_debug; | |
316 | bool sig_ok; | |
317 | #ifdef CONFIG_KALLSYMS | |
318 | unsigned long mod_kallsyms_init_off; | |
319 | #endif | |
320 | struct { | |
321 | unsigned int sym, str, mod, vers, info, pcpu; | |
322 | } index; | |
323 | }; | |
324 | ||
325 | /* | |
326 | * We require a truly strong try_module_get(): 0 means success. | |
327 | * Otherwise an error is returned due to ongoing or failed | |
328 | * initialization etc. | |
329 | */ | |
330 | static inline int strong_try_module_get(struct module *mod) | |
331 | { | |
332 | BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED); | |
333 | if (mod && mod->state == MODULE_STATE_COMING) | |
334 | return -EBUSY; | |
335 | if (try_module_get(mod)) | |
336 | return 0; | |
337 | else | |
338 | return -ENOENT; | |
339 | } | |
340 | ||
341 | static inline void add_taint_module(struct module *mod, unsigned flag, | |
342 | enum lockdep_ok lockdep_ok) | |
343 | { | |
344 | add_taint(flag, lockdep_ok); | |
345 | set_bit(flag, &mod->taints); | |
346 | } | |
347 | ||
348 | /* | |
349 | * A thread that wants to hold a reference to a module only while it | |
350 | * is running can call this to safely exit. nfsd and lockd use this. | |
351 | */ | |
352 | void __noreturn __module_put_and_exit(struct module *mod, long code) | |
353 | { | |
354 | module_put(mod); | |
355 | do_exit(code); | |
356 | } | |
357 | EXPORT_SYMBOL(__module_put_and_exit); | |
358 | ||
359 | /* Find a module section: 0 means not found. */ | |
360 | static unsigned int find_sec(const struct load_info *info, const char *name) | |
361 | { | |
362 | unsigned int i; | |
363 | ||
364 | for (i = 1; i < info->hdr->e_shnum; i++) { | |
365 | Elf_Shdr *shdr = &info->sechdrs[i]; | |
366 | /* Alloc bit cleared means "ignore it." */ | |
367 | if ((shdr->sh_flags & SHF_ALLOC) | |
368 | && strcmp(info->secstrings + shdr->sh_name, name) == 0) | |
369 | return i; | |
370 | } | |
371 | return 0; | |
372 | } | |
373 | ||
374 | /* Find a module section, or NULL. */ | |
375 | static void *section_addr(const struct load_info *info, const char *name) | |
376 | { | |
377 | /* Section 0 has sh_addr 0. */ | |
378 | return (void *)info->sechdrs[find_sec(info, name)].sh_addr; | |
379 | } | |
380 | ||
381 | /* Find a module section, or NULL. Fill in number of "objects" in section. */ | |
382 | static void *section_objs(const struct load_info *info, | |
383 | const char *name, | |
384 | size_t object_size, | |
385 | unsigned int *num) | |
386 | { | |
387 | unsigned int sec = find_sec(info, name); | |
388 | ||
389 | /* Section 0 has sh_addr 0 and sh_size 0. */ | |
390 | *num = info->sechdrs[sec].sh_size / object_size; | |
391 | return (void *)info->sechdrs[sec].sh_addr; | |
392 | } | |
393 | ||
394 | /* Provided by the linker */ | |
395 | extern const struct kernel_symbol __start___ksymtab[]; | |
396 | extern const struct kernel_symbol __stop___ksymtab[]; | |
397 | extern const struct kernel_symbol __start___ksymtab_gpl[]; | |
398 | extern const struct kernel_symbol __stop___ksymtab_gpl[]; | |
399 | extern const struct kernel_symbol __start___ksymtab_gpl_future[]; | |
400 | extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; | |
401 | extern const s32 __start___kcrctab[]; | |
402 | extern const s32 __start___kcrctab_gpl[]; | |
403 | extern const s32 __start___kcrctab_gpl_future[]; | |
404 | #ifdef CONFIG_UNUSED_SYMBOLS | |
405 | extern const struct kernel_symbol __start___ksymtab_unused[]; | |
406 | extern const struct kernel_symbol __stop___ksymtab_unused[]; | |
407 | extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; | |
408 | extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; | |
409 | extern const s32 __start___kcrctab_unused[]; | |
410 | extern const s32 __start___kcrctab_unused_gpl[]; | |
411 | #endif | |
412 | ||
413 | #ifndef CONFIG_MODVERSIONS | |
414 | #define symversion(base, idx) NULL | |
415 | #else | |
416 | #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) | |
417 | #endif | |
418 | ||
419 | static bool each_symbol_in_section(const struct symsearch *arr, | |
420 | unsigned int arrsize, | |
421 | struct module *owner, | |
422 | bool (*fn)(const struct symsearch *syms, | |
423 | struct module *owner, | |
424 | void *data), | |
425 | void *data) | |
426 | { | |
427 | unsigned int j; | |
428 | ||
429 | for (j = 0; j < arrsize; j++) { | |
430 | if (fn(&arr[j], owner, data)) | |
431 | return true; | |
432 | } | |
433 | ||
434 | return false; | |
435 | } | |
436 | ||
437 | /* Returns true as soon as fn returns true, otherwise false. */ | |
438 | bool each_symbol_section(bool (*fn)(const struct symsearch *arr, | |
439 | struct module *owner, | |
440 | void *data), | |
441 | void *data) | |
442 | { | |
443 | struct module *mod; | |
444 | static const struct symsearch arr[] = { | |
445 | { __start___ksymtab, __stop___ksymtab, __start___kcrctab, | |
446 | NOT_GPL_ONLY, false }, | |
447 | { __start___ksymtab_gpl, __stop___ksymtab_gpl, | |
448 | __start___kcrctab_gpl, | |
449 | GPL_ONLY, false }, | |
450 | { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, | |
451 | __start___kcrctab_gpl_future, | |
452 | WILL_BE_GPL_ONLY, false }, | |
453 | #ifdef CONFIG_UNUSED_SYMBOLS | |
454 | { __start___ksymtab_unused, __stop___ksymtab_unused, | |
455 | __start___kcrctab_unused, | |
456 | NOT_GPL_ONLY, true }, | |
457 | { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, | |
458 | __start___kcrctab_unused_gpl, | |
459 | GPL_ONLY, true }, | |
460 | #endif | |
461 | }; | |
462 | ||
463 | module_assert_mutex_or_preempt(); | |
464 | ||
465 | if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) | |
466 | return true; | |
467 | ||
468 | list_for_each_entry_rcu(mod, &modules, list) { | |
469 | struct symsearch arr[] = { | |
470 | { mod->syms, mod->syms + mod->num_syms, mod->crcs, | |
471 | NOT_GPL_ONLY, false }, | |
472 | { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, | |
473 | mod->gpl_crcs, | |
474 | GPL_ONLY, false }, | |
475 | { mod->gpl_future_syms, | |
476 | mod->gpl_future_syms + mod->num_gpl_future_syms, | |
477 | mod->gpl_future_crcs, | |
478 | WILL_BE_GPL_ONLY, false }, | |
479 | #ifdef CONFIG_UNUSED_SYMBOLS | |
480 | { mod->unused_syms, | |
481 | mod->unused_syms + mod->num_unused_syms, | |
482 | mod->unused_crcs, | |
483 | NOT_GPL_ONLY, true }, | |
484 | { mod->unused_gpl_syms, | |
485 | mod->unused_gpl_syms + mod->num_unused_gpl_syms, | |
486 | mod->unused_gpl_crcs, | |
487 | GPL_ONLY, true }, | |
488 | #endif | |
489 | }; | |
490 | ||
491 | if (mod->state == MODULE_STATE_UNFORMED) | |
492 | continue; | |
493 | ||
494 | if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) | |
495 | return true; | |
496 | } | |
497 | return false; | |
498 | } | |
499 | EXPORT_SYMBOL_GPL(each_symbol_section); | |
500 | ||
501 | struct find_symbol_arg { | |
502 | /* Input */ | |
503 | const char *name; | |
504 | bool gplok; | |
505 | bool warn; | |
506 | ||
507 | /* Output */ | |
508 | struct module *owner; | |
509 | const s32 *crc; | |
510 | const struct kernel_symbol *sym; | |
511 | }; | |
512 | ||
513 | static bool check_symbol(const struct symsearch *syms, | |
514 | struct module *owner, | |
515 | unsigned int symnum, void *data) | |
516 | { | |
517 | struct find_symbol_arg *fsa = data; | |
518 | ||
519 | if (!fsa->gplok) { | |
520 | if (syms->licence == GPL_ONLY) | |
521 | return false; | |
522 | if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { | |
523 | pr_warn("Symbol %s is being used by a non-GPL module, " | |
524 | "which will not be allowed in the future\n", | |
525 | fsa->name); | |
526 | } | |
527 | } | |
528 | ||
529 | #ifdef CONFIG_UNUSED_SYMBOLS | |
530 | if (syms->unused && fsa->warn) { | |
531 | pr_warn("Symbol %s is marked as UNUSED, however this module is " | |
532 | "using it.\n", fsa->name); | |
533 | pr_warn("This symbol will go away in the future.\n"); | |
534 | pr_warn("Please evaluate if this is the right api to use and " | |
535 | "if it really is, submit a report to the linux kernel " | |
536 | "mailing list together with submitting your code for " | |
537 | "inclusion.\n"); | |
538 | } | |
539 | #endif | |
540 | ||
541 | fsa->owner = owner; | |
542 | fsa->crc = symversion(syms->crcs, symnum); | |
543 | fsa->sym = &syms->start[symnum]; | |
544 | return true; | |
545 | } | |
546 | ||
547 | static int cmp_name(const void *va, const void *vb) | |
548 | { | |
549 | const char *a; | |
550 | const struct kernel_symbol *b; | |
551 | a = va; b = vb; | |
552 | return strcmp(a, b->name); | |
553 | } | |
554 | ||
555 | static bool find_symbol_in_section(const struct symsearch *syms, | |
556 | struct module *owner, | |
557 | void *data) | |
558 | { | |
559 | struct find_symbol_arg *fsa = data; | |
560 | struct kernel_symbol *sym; | |
561 | ||
562 | sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, | |
563 | sizeof(struct kernel_symbol), cmp_name); | |
564 | ||
565 | if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data)) | |
566 | return true; | |
567 | ||
568 | return false; | |
569 | } | |
570 | ||
571 | /* Find a symbol and return it, along with, (optional) crc and | |
572 | * (optional) module which owns it. Needs preempt disabled or module_mutex. */ | |
573 | const struct kernel_symbol *find_symbol(const char *name, | |
574 | struct module **owner, | |
575 | const s32 **crc, | |
576 | bool gplok, | |
577 | bool warn) | |
578 | { | |
579 | struct find_symbol_arg fsa; | |
580 | ||
581 | fsa.name = name; | |
582 | fsa.gplok = gplok; | |
583 | fsa.warn = warn; | |
584 | ||
585 | if (each_symbol_section(find_symbol_in_section, &fsa)) { | |
586 | if (owner) | |
587 | *owner = fsa.owner; | |
588 | if (crc) | |
589 | *crc = fsa.crc; | |
590 | return fsa.sym; | |
591 | } | |
592 | ||
593 | pr_debug("Failed to find symbol %s\n", name); | |
594 | return NULL; | |
595 | } | |
596 | EXPORT_SYMBOL_GPL(find_symbol); | |
597 | ||
598 | /* | |
599 | * Search for module by name: must hold module_mutex (or preempt disabled | |
600 | * for read-only access). | |
601 | */ | |
602 | static struct module *find_module_all(const char *name, size_t len, | |
603 | bool even_unformed) | |
604 | { | |
605 | struct module *mod; | |
606 | ||
607 | module_assert_mutex_or_preempt(); | |
608 | ||
609 | list_for_each_entry_rcu(mod, &modules, list) { | |
610 | if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) | |
611 | continue; | |
612 | if (strlen(mod->name) == len && !memcmp(mod->name, name, len)) | |
613 | return mod; | |
614 | } | |
615 | return NULL; | |
616 | } | |
617 | ||
618 | struct module *find_module(const char *name) | |
619 | { | |
620 | module_assert_mutex(); | |
621 | return find_module_all(name, strlen(name), false); | |
622 | } | |
623 | EXPORT_SYMBOL_GPL(find_module); | |
624 | ||
625 | #ifdef CONFIG_SMP | |
626 | ||
627 | static inline void __percpu *mod_percpu(struct module *mod) | |
628 | { | |
629 | return mod->percpu; | |
630 | } | |
631 | ||
632 | static int percpu_modalloc(struct module *mod, struct load_info *info) | |
633 | { | |
634 | Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu]; | |
635 | unsigned long align = pcpusec->sh_addralign; | |
636 | ||
637 | if (!pcpusec->sh_size) | |
638 | return 0; | |
639 | ||
640 | if (align > PAGE_SIZE) { | |
641 | pr_warn("%s: per-cpu alignment %li > %li\n", | |
642 | mod->name, align, PAGE_SIZE); | |
643 | align = PAGE_SIZE; | |
644 | } | |
645 | ||
646 | mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align); | |
647 | if (!mod->percpu) { | |
648 | pr_warn("%s: Could not allocate %lu bytes percpu data\n", | |
649 | mod->name, (unsigned long)pcpusec->sh_size); | |
650 | return -ENOMEM; | |
651 | } | |
652 | mod->percpu_size = pcpusec->sh_size; | |
653 | return 0; | |
654 | } | |
655 | ||
656 | static void percpu_modfree(struct module *mod) | |
657 | { | |
658 | free_percpu(mod->percpu); | |
659 | } | |
660 | ||
661 | static unsigned int find_pcpusec(struct load_info *info) | |
662 | { | |
663 | return find_sec(info, ".data..percpu"); | |
664 | } | |
665 | ||
666 | static void percpu_modcopy(struct module *mod, | |
667 | const void *from, unsigned long size) | |
668 | { | |
669 | int cpu; | |
670 | ||
671 | for_each_possible_cpu(cpu) | |
672 | memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); | |
673 | } | |
674 | ||
675 | bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) | |
676 | { | |
677 | struct module *mod; | |
678 | unsigned int cpu; | |
679 | ||
680 | preempt_disable(); | |
681 | ||
682 | list_for_each_entry_rcu(mod, &modules, list) { | |
683 | if (mod->state == MODULE_STATE_UNFORMED) | |
684 | continue; | |
685 | if (!mod->percpu_size) | |
686 | continue; | |
687 | for_each_possible_cpu(cpu) { | |
688 | void *start = per_cpu_ptr(mod->percpu, cpu); | |
689 | void *va = (void *)addr; | |
690 | ||
691 | if (va >= start && va < start + mod->percpu_size) { | |
692 | if (can_addr) { | |
693 | *can_addr = (unsigned long) (va - start); | |
694 | *can_addr += (unsigned long) | |
695 | per_cpu_ptr(mod->percpu, | |
696 | get_boot_cpu_id()); | |
697 | } | |
698 | preempt_enable(); | |
699 | return true; | |
700 | } | |
701 | } | |
702 | } | |
703 | ||
704 | preempt_enable(); | |
705 | return false; | |
706 | } | |
707 | ||
708 | /** | |
709 | * is_module_percpu_address - test whether address is from module static percpu | |
710 | * @addr: address to test | |
711 | * | |
712 | * Test whether @addr belongs to module static percpu area. | |
713 | * | |
714 | * RETURNS: | |
715 | * %true if @addr is from module static percpu area | |
716 | */ | |
717 | bool is_module_percpu_address(unsigned long addr) | |
718 | { | |
719 | return __is_module_percpu_address(addr, NULL); | |
720 | } | |
721 | ||
722 | #else /* ... !CONFIG_SMP */ | |
723 | ||
724 | static inline void __percpu *mod_percpu(struct module *mod) | |
725 | { | |
726 | return NULL; | |
727 | } | |
728 | static int percpu_modalloc(struct module *mod, struct load_info *info) | |
729 | { | |
730 | /* UP modules shouldn't have this section: ENOMEM isn't quite right */ | |
731 | if (info->sechdrs[info->index.pcpu].sh_size != 0) | |
732 | return -ENOMEM; | |
733 | return 0; | |
734 | } | |
735 | static inline void percpu_modfree(struct module *mod) | |
736 | { | |
737 | } | |
738 | static unsigned int find_pcpusec(struct load_info *info) | |
739 | { | |
740 | return 0; | |
741 | } | |
742 | static inline void percpu_modcopy(struct module *mod, | |
743 | const void *from, unsigned long size) | |
744 | { | |
745 | /* pcpusec should be 0, and size of that section should be 0. */ | |
746 | BUG_ON(size != 0); | |
747 | } | |
748 | bool is_module_percpu_address(unsigned long addr) | |
749 | { | |
750 | return false; | |
751 | } | |
752 | ||
753 | bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) | |
754 | { | |
755 | return false; | |
756 | } | |
757 | ||
758 | #endif /* CONFIG_SMP */ | |
759 | ||
760 | #define MODINFO_ATTR(field) \ | |
761 | static void setup_modinfo_##field(struct module *mod, const char *s) \ | |
762 | { \ | |
763 | mod->field = kstrdup(s, GFP_KERNEL); \ | |
764 | } \ | |
765 | static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ | |
766 | struct module_kobject *mk, char *buffer) \ | |
767 | { \ | |
768 | return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \ | |
769 | } \ | |
770 | static int modinfo_##field##_exists(struct module *mod) \ | |
771 | { \ | |
772 | return mod->field != NULL; \ | |
773 | } \ | |
774 | static void free_modinfo_##field(struct module *mod) \ | |
775 | { \ | |
776 | kfree(mod->field); \ | |
777 | mod->field = NULL; \ | |
778 | } \ | |
779 | static struct module_attribute modinfo_##field = { \ | |
780 | .attr = { .name = __stringify(field), .mode = 0444 }, \ | |
781 | .show = show_modinfo_##field, \ | |
782 | .setup = setup_modinfo_##field, \ | |
783 | .test = modinfo_##field##_exists, \ | |
784 | .free = free_modinfo_##field, \ | |
785 | }; | |
786 | ||
787 | MODINFO_ATTR(version); | |
788 | MODINFO_ATTR(srcversion); | |
789 | ||
790 | static char last_unloaded_module[MODULE_NAME_LEN+1]; | |
791 | ||
792 | #ifdef CONFIG_MODULE_UNLOAD | |
793 | ||
794 | EXPORT_TRACEPOINT_SYMBOL(module_get); | |
795 | ||
796 | /* MODULE_REF_BASE is the base reference count by kmodule loader. */ | |
797 | #define MODULE_REF_BASE 1 | |
798 | ||
799 | /* Init the unload section of the module. */ | |
800 | static int module_unload_init(struct module *mod) | |
801 | { | |
802 | /* | |
803 | * Initialize reference counter to MODULE_REF_BASE. | |
804 | * refcnt == 0 means module is going. | |
805 | */ | |
806 | atomic_set(&mod->refcnt, MODULE_REF_BASE); | |
807 | ||
808 | INIT_LIST_HEAD(&mod->source_list); | |
809 | INIT_LIST_HEAD(&mod->target_list); | |
810 | ||
811 | /* Hold reference count during initialization. */ | |
812 | atomic_inc(&mod->refcnt); | |
813 | ||
814 | return 0; | |
815 | } | |
816 | ||
817 | /* Does a already use b? */ | |
818 | static int already_uses(struct module *a, struct module *b) | |
819 | { | |
820 | struct module_use *use; | |
821 | ||
822 | list_for_each_entry(use, &b->source_list, source_list) { | |
823 | if (use->source == a) { | |
824 | pr_debug("%s uses %s!\n", a->name, b->name); | |
825 | return 1; | |
826 | } | |
827 | } | |
828 | pr_debug("%s does not use %s!\n", a->name, b->name); | |
829 | return 0; | |
830 | } | |
831 | ||
832 | /* | |
833 | * Module a uses b | |
834 | * - we add 'a' as a "source", 'b' as a "target" of module use | |
835 | * - the module_use is added to the list of 'b' sources (so | |
836 | * 'b' can walk the list to see who sourced them), and of 'a' | |
837 | * targets (so 'a' can see what modules it targets). | |
838 | */ | |
839 | static int add_module_usage(struct module *a, struct module *b) | |
840 | { | |
841 | struct module_use *use; | |
842 | ||
843 | pr_debug("Allocating new usage for %s.\n", a->name); | |
844 | use = kmalloc(sizeof(*use), GFP_ATOMIC); | |
845 | if (!use) | |
846 | return -ENOMEM; | |
847 | ||
848 | use->source = a; | |
849 | use->target = b; | |
850 | list_add(&use->source_list, &b->source_list); | |
851 | list_add(&use->target_list, &a->target_list); | |
852 | return 0; | |
853 | } | |
854 | ||
855 | /* Module a uses b: caller needs module_mutex() */ | |
856 | int ref_module(struct module *a, struct module *b) | |
857 | { | |
858 | int err; | |
859 | ||
860 | if (b == NULL || already_uses(a, b)) | |
861 | return 0; | |
862 | ||
863 | /* If module isn't available, we fail. */ | |
864 | err = strong_try_module_get(b); | |
865 | if (err) | |
866 | return err; | |
867 | ||
868 | err = add_module_usage(a, b); | |
869 | if (err) { | |
870 | module_put(b); | |
871 | return err; | |
872 | } | |
873 | return 0; | |
874 | } | |
875 | EXPORT_SYMBOL_GPL(ref_module); | |
876 | ||
877 | /* Clear the unload stuff of the module. */ | |
878 | static void module_unload_free(struct module *mod) | |
879 | { | |
880 | struct module_use *use, *tmp; | |
881 | ||
882 | mutex_lock(&module_mutex); | |
883 | list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { | |
884 | struct module *i = use->target; | |
885 | pr_debug("%s unusing %s\n", mod->name, i->name); | |
886 | module_put(i); | |
887 | list_del(&use->source_list); | |
888 | list_del(&use->target_list); | |
889 | kfree(use); | |
890 | } | |
891 | mutex_unlock(&module_mutex); | |
892 | } | |
893 | ||
894 | #ifdef CONFIG_MODULE_FORCE_UNLOAD | |
895 | static inline int try_force_unload(unsigned int flags) | |
896 | { | |
897 | int ret = (flags & O_TRUNC); | |
898 | if (ret) | |
899 | add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); | |
900 | return ret; | |
901 | } | |
902 | #else | |
903 | static inline int try_force_unload(unsigned int flags) | |
904 | { | |
905 | return 0; | |
906 | } | |
907 | #endif /* CONFIG_MODULE_FORCE_UNLOAD */ | |
908 | ||
909 | /* Try to release refcount of module, 0 means success. */ | |
910 | static int try_release_module_ref(struct module *mod) | |
911 | { | |
912 | int ret; | |
913 | ||
914 | /* Try to decrement refcnt which we set at loading */ | |
915 | ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt); | |
916 | BUG_ON(ret < 0); | |
917 | if (ret) | |
918 | /* Someone can put this right now, recover with checking */ | |
919 | ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0); | |
920 | ||
921 | return ret; | |
922 | } | |
923 | ||
924 | static int try_stop_module(struct module *mod, int flags, int *forced) | |
925 | { | |
926 | /* If it's not unused, quit unless we're forcing. */ | |
927 | if (try_release_module_ref(mod) != 0) { | |
928 | *forced = try_force_unload(flags); | |
929 | if (!(*forced)) | |
930 | return -EWOULDBLOCK; | |
931 | } | |
932 | ||
933 | /* Mark it as dying. */ | |
934 | mod->state = MODULE_STATE_GOING; | |
935 | ||
936 | return 0; | |
937 | } | |
938 | ||
939 | /** | |
940 | * module_refcount - return the refcount or -1 if unloading | |
941 | * | |
942 | * @mod: the module we're checking | |
943 | * | |
944 | * Returns: | |
945 | * -1 if the module is in the process of unloading | |
946 | * otherwise the number of references in the kernel to the module | |
947 | */ | |
948 | int module_refcount(struct module *mod) | |
949 | { | |
950 | return atomic_read(&mod->refcnt) - MODULE_REF_BASE; | |
951 | } | |
952 | EXPORT_SYMBOL(module_refcount); | |
953 | ||
954 | /* This exists whether we can unload or not */ | |
955 | static void free_module(struct module *mod); | |
956 | ||
957 | SYSCALL_DEFINE2(delete_module, const char __user *, name_user, | |
958 | unsigned int, flags) | |
959 | { | |
960 | struct module *mod; | |
961 | char name[MODULE_NAME_LEN]; | |
962 | int ret, forced = 0; | |
963 | ||
964 | if (!capable(CAP_SYS_MODULE) || modules_disabled) | |
965 | return -EPERM; | |
966 | ||
967 | if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) | |
968 | return -EFAULT; | |
969 | name[MODULE_NAME_LEN-1] = '\0'; | |
970 | ||
971 | audit_log_kern_module(name); | |
972 | ||
973 | if (mutex_lock_interruptible(&module_mutex) != 0) | |
974 | return -EINTR; | |
975 | ||
976 | mod = find_module(name); | |
977 | if (!mod) { | |
978 | ret = -ENOENT; | |
979 | goto out; | |
980 | } | |
981 | ||
982 | if (!list_empty(&mod->source_list)) { | |
983 | /* Other modules depend on us: get rid of them first. */ | |
984 | ret = -EWOULDBLOCK; | |
985 | goto out; | |
986 | } | |
987 | ||
988 | /* Doing init or already dying? */ | |
989 | if (mod->state != MODULE_STATE_LIVE) { | |
990 | /* FIXME: if (force), slam module count damn the torpedoes */ | |
991 | pr_debug("%s already dying\n", mod->name); | |
992 | ret = -EBUSY; | |
993 | goto out; | |
994 | } | |
995 | ||
996 | /* If it has an init func, it must have an exit func to unload */ | |
997 | if (mod->init && !mod->exit) { | |
998 | forced = try_force_unload(flags); | |
999 | if (!forced) { | |
1000 | /* This module can't be removed */ | |
1001 | ret = -EBUSY; | |
1002 | goto out; | |
1003 | } | |
1004 | } | |
1005 | ||
1006 | /* Stop the machine so refcounts can't move and disable module. */ | |
1007 | ret = try_stop_module(mod, flags, &forced); | |
1008 | if (ret != 0) | |
1009 | goto out; | |
1010 | ||
1011 | mutex_unlock(&module_mutex); | |
1012 | /* Final destruction now no one is using it. */ | |
1013 | if (mod->exit != NULL) | |
1014 | mod->exit(); | |
1015 | blocking_notifier_call_chain(&module_notify_list, | |
1016 | MODULE_STATE_GOING, mod); | |
1017 | klp_module_going(mod); | |
1018 | ftrace_release_mod(mod); | |
1019 | ||
1020 | async_synchronize_full(); | |
1021 | ||
1022 | /* Store the name of the last unloaded module for diagnostic purposes */ | |
1023 | strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); | |
1024 | ||
1025 | free_module(mod); | |
1026 | /* someone could wait for the module in add_unformed_module() */ | |
1027 | wake_up_all(&module_wq); | |
1028 | return 0; | |
1029 | out: | |
1030 | mutex_unlock(&module_mutex); | |
1031 | return ret; | |
1032 | } | |
1033 | ||
1034 | static inline void print_unload_info(struct seq_file *m, struct module *mod) | |
1035 | { | |
1036 | struct module_use *use; | |
1037 | int printed_something = 0; | |
1038 | ||
1039 | seq_printf(m, " %i ", module_refcount(mod)); | |
1040 | ||
1041 | /* | |
1042 | * Always include a trailing , so userspace can differentiate | |
1043 | * between this and the old multi-field proc format. | |
1044 | */ | |
1045 | list_for_each_entry(use, &mod->source_list, source_list) { | |
1046 | printed_something = 1; | |
1047 | seq_printf(m, "%s,", use->source->name); | |
1048 | } | |
1049 | ||
1050 | if (mod->init != NULL && mod->exit == NULL) { | |
1051 | printed_something = 1; | |
1052 | seq_puts(m, "[permanent],"); | |
1053 | } | |
1054 | ||
1055 | if (!printed_something) | |
1056 | seq_puts(m, "-"); | |
1057 | } | |
1058 | ||
1059 | void __symbol_put(const char *symbol) | |
1060 | { | |
1061 | struct module *owner; | |
1062 | ||
1063 | preempt_disable(); | |
1064 | if (!find_symbol(symbol, &owner, NULL, true, false)) | |
1065 | BUG(); | |
1066 | module_put(owner); | |
1067 | preempt_enable(); | |
1068 | } | |
1069 | EXPORT_SYMBOL(__symbol_put); | |
1070 | ||
1071 | /* Note this assumes addr is a function, which it currently always is. */ | |
1072 | void symbol_put_addr(void *addr) | |
1073 | { | |
1074 | struct module *modaddr; | |
1075 | unsigned long a = (unsigned long)dereference_function_descriptor(addr); | |
1076 | ||
1077 | if (core_kernel_text(a)) | |
1078 | return; | |
1079 | ||
1080 | /* | |
1081 | * Even though we hold a reference on the module; we still need to | |
1082 | * disable preemption in order to safely traverse the data structure. | |
1083 | */ | |
1084 | preempt_disable(); | |
1085 | modaddr = __module_text_address(a); | |
1086 | BUG_ON(!modaddr); | |
1087 | module_put(modaddr); | |
1088 | preempt_enable(); | |
1089 | } | |
1090 | EXPORT_SYMBOL_GPL(symbol_put_addr); | |
1091 | ||
1092 | static ssize_t show_refcnt(struct module_attribute *mattr, | |
1093 | struct module_kobject *mk, char *buffer) | |
1094 | { | |
1095 | return sprintf(buffer, "%i\n", module_refcount(mk->mod)); | |
1096 | } | |
1097 | ||
1098 | static struct module_attribute modinfo_refcnt = | |
1099 | __ATTR(refcnt, 0444, show_refcnt, NULL); | |
1100 | ||
1101 | void __module_get(struct module *module) | |
1102 | { | |
1103 | if (module) { | |
1104 | preempt_disable(); | |
1105 | atomic_inc(&module->refcnt); | |
1106 | trace_module_get(module, _RET_IP_); | |
1107 | preempt_enable(); | |
1108 | } | |
1109 | } | |
1110 | EXPORT_SYMBOL(__module_get); | |
1111 | ||
1112 | bool try_module_get(struct module *module) | |
1113 | { | |
1114 | bool ret = true; | |
1115 | ||
1116 | if (module) { | |
1117 | preempt_disable(); | |
1118 | /* Note: here, we can fail to get a reference */ | |
1119 | if (likely(module_is_live(module) && | |
1120 | atomic_inc_not_zero(&module->refcnt) != 0)) | |
1121 | trace_module_get(module, _RET_IP_); | |
1122 | else | |
1123 | ret = false; | |
1124 | ||
1125 | preempt_enable(); | |
1126 | } | |
1127 | return ret; | |
1128 | } | |
1129 | EXPORT_SYMBOL(try_module_get); | |
1130 | ||
1131 | void module_put(struct module *module) | |
1132 | { | |
1133 | int ret; | |
1134 | ||
1135 | if (module) { | |
1136 | preempt_disable(); | |
1137 | ret = atomic_dec_if_positive(&module->refcnt); | |
1138 | WARN_ON(ret < 0); /* Failed to put refcount */ | |
1139 | trace_module_put(module, _RET_IP_); | |
1140 | preempt_enable(); | |
1141 | } | |
1142 | } | |
1143 | EXPORT_SYMBOL(module_put); | |
1144 | ||
1145 | #else /* !CONFIG_MODULE_UNLOAD */ | |
1146 | static inline void print_unload_info(struct seq_file *m, struct module *mod) | |
1147 | { | |
1148 | /* We don't know the usage count, or what modules are using. */ | |
1149 | seq_puts(m, " - -"); | |
1150 | } | |
1151 | ||
1152 | static inline void module_unload_free(struct module *mod) | |
1153 | { | |
1154 | } | |
1155 | ||
1156 | int ref_module(struct module *a, struct module *b) | |
1157 | { | |
1158 | return strong_try_module_get(b); | |
1159 | } | |
1160 | EXPORT_SYMBOL_GPL(ref_module); | |
1161 | ||
1162 | static inline int module_unload_init(struct module *mod) | |
1163 | { | |
1164 | return 0; | |
1165 | } | |
1166 | #endif /* CONFIG_MODULE_UNLOAD */ | |
1167 | ||
1168 | static size_t module_flags_taint(struct module *mod, char *buf) | |
1169 | { | |
1170 | size_t l = 0; | |
1171 | int i; | |
1172 | ||
1173 | for (i = 0; i < TAINT_FLAGS_COUNT; i++) { | |
1174 | if (taint_flags[i].module && test_bit(i, &mod->taints)) | |
1175 | buf[l++] = taint_flags[i].c_true; | |
1176 | } | |
1177 | ||
1178 | return l; | |
1179 | } | |
1180 | ||
1181 | static ssize_t show_initstate(struct module_attribute *mattr, | |
1182 | struct module_kobject *mk, char *buffer) | |
1183 | { | |
1184 | const char *state = "unknown"; | |
1185 | ||
1186 | switch (mk->mod->state) { | |
1187 | case MODULE_STATE_LIVE: | |
1188 | state = "live"; | |
1189 | break; | |
1190 | case MODULE_STATE_COMING: | |
1191 | state = "coming"; | |
1192 | break; | |
1193 | case MODULE_STATE_GOING: | |
1194 | state = "going"; | |
1195 | break; | |
1196 | default: | |
1197 | BUG(); | |
1198 | } | |
1199 | return sprintf(buffer, "%s\n", state); | |
1200 | } | |
1201 | ||
1202 | static struct module_attribute modinfo_initstate = | |
1203 | __ATTR(initstate, 0444, show_initstate, NULL); | |
1204 | ||
1205 | static ssize_t store_uevent(struct module_attribute *mattr, | |
1206 | struct module_kobject *mk, | |
1207 | const char *buffer, size_t count) | |
1208 | { | |
1209 | int rc; | |
1210 | ||
1211 | rc = kobject_synth_uevent(&mk->kobj, buffer, count); | |
1212 | return rc ? rc : count; | |
1213 | } | |
1214 | ||
1215 | struct module_attribute module_uevent = | |
1216 | __ATTR(uevent, 0200, NULL, store_uevent); | |
1217 | ||
1218 | static ssize_t show_coresize(struct module_attribute *mattr, | |
1219 | struct module_kobject *mk, char *buffer) | |
1220 | { | |
1221 | return sprintf(buffer, "%u\n", mk->mod->core_layout.size); | |
1222 | } | |
1223 | ||
1224 | static struct module_attribute modinfo_coresize = | |
1225 | __ATTR(coresize, 0444, show_coresize, NULL); | |
1226 | ||
1227 | static ssize_t show_initsize(struct module_attribute *mattr, | |
1228 | struct module_kobject *mk, char *buffer) | |
1229 | { | |
1230 | return sprintf(buffer, "%u\n", mk->mod->init_layout.size); | |
1231 | } | |
1232 | ||
1233 | static struct module_attribute modinfo_initsize = | |
1234 | __ATTR(initsize, 0444, show_initsize, NULL); | |
1235 | ||
1236 | static ssize_t show_taint(struct module_attribute *mattr, | |
1237 | struct module_kobject *mk, char *buffer) | |
1238 | { | |
1239 | size_t l; | |
1240 | ||
1241 | l = module_flags_taint(mk->mod, buffer); | |
1242 | buffer[l++] = '\n'; | |
1243 | return l; | |
1244 | } | |
1245 | ||
1246 | static struct module_attribute modinfo_taint = | |
1247 | __ATTR(taint, 0444, show_taint, NULL); | |
1248 | ||
1249 | static struct module_attribute *modinfo_attrs[] = { | |
1250 | &module_uevent, | |
1251 | &modinfo_version, | |
1252 | &modinfo_srcversion, | |
1253 | &modinfo_initstate, | |
1254 | &modinfo_coresize, | |
1255 | &modinfo_initsize, | |
1256 | &modinfo_taint, | |
1257 | #ifdef CONFIG_MODULE_UNLOAD | |
1258 | &modinfo_refcnt, | |
1259 | #endif | |
1260 | NULL, | |
1261 | }; | |
1262 | ||
1263 | static const char vermagic[] = VERMAGIC_STRING; | |
1264 | ||
1265 | static int try_to_force_load(struct module *mod, const char *reason) | |
1266 | { | |
1267 | #ifdef CONFIG_MODULE_FORCE_LOAD | |
1268 | if (!test_taint(TAINT_FORCED_MODULE)) | |
1269 | pr_warn("%s: %s: kernel tainted.\n", mod->name, reason); | |
1270 | add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE); | |
1271 | return 0; | |
1272 | #else | |
1273 | return -ENOEXEC; | |
1274 | #endif | |
1275 | } | |
1276 | ||
1277 | #ifdef CONFIG_MODVERSIONS | |
1278 | ||
1279 | static u32 resolve_rel_crc(const s32 *crc) | |
1280 | { | |
1281 | return *(u32 *)((void *)crc + *crc); | |
1282 | } | |
1283 | ||
1284 | static int check_version(const struct load_info *info, | |
1285 | const char *symname, | |
1286 | struct module *mod, | |
1287 | const s32 *crc) | |
1288 | { | |
1289 | Elf_Shdr *sechdrs = info->sechdrs; | |
1290 | unsigned int versindex = info->index.vers; | |
1291 | unsigned int i, num_versions; | |
1292 | struct modversion_info *versions; | |
1293 | ||
1294 | /* Exporting module didn't supply crcs? OK, we're already tainted. */ | |
1295 | if (!crc) | |
1296 | return 1; | |
1297 | ||
1298 | /* No versions at all? modprobe --force does this. */ | |
1299 | if (versindex == 0) | |
1300 | return try_to_force_load(mod, symname) == 0; | |
1301 | ||
1302 | versions = (void *) sechdrs[versindex].sh_addr; | |
1303 | num_versions = sechdrs[versindex].sh_size | |
1304 | / sizeof(struct modversion_info); | |
1305 | ||
1306 | for (i = 0; i < num_versions; i++) { | |
1307 | u32 crcval; | |
1308 | ||
1309 | if (strcmp(versions[i].name, symname) != 0) | |
1310 | continue; | |
1311 | ||
1312 | if (IS_ENABLED(CONFIG_MODULE_REL_CRCS)) | |
1313 | crcval = resolve_rel_crc(crc); | |
1314 | else | |
1315 | crcval = *crc; | |
1316 | if (versions[i].crc == crcval) | |
1317 | return 1; | |
1318 | pr_debug("Found checksum %X vs module %lX\n", | |
1319 | crcval, versions[i].crc); | |
1320 | goto bad_version; | |
1321 | } | |
1322 | ||
1323 | /* Broken toolchain. Warn once, then let it go.. */ | |
1324 | pr_warn_once("%s: no symbol version for %s\n", info->name, symname); | |
1325 | return 1; | |
1326 | ||
1327 | bad_version: | |
1328 | pr_warn("%s: disagrees about version of symbol %s\n", | |
1329 | info->name, symname); | |
1330 | return 0; | |
1331 | } | |
1332 | ||
1333 | static inline int check_modstruct_version(const struct load_info *info, | |
1334 | struct module *mod) | |
1335 | { | |
1336 | const s32 *crc; | |
1337 | ||
1338 | /* | |
1339 | * Since this should be found in kernel (which can't be removed), no | |
1340 | * locking is necessary -- use preempt_disable() to placate lockdep. | |
1341 | */ | |
1342 | preempt_disable(); | |
1343 | if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL, | |
1344 | &crc, true, false)) { | |
1345 | preempt_enable(); | |
1346 | BUG(); | |
1347 | } | |
1348 | preempt_enable(); | |
1349 | return check_version(info, VMLINUX_SYMBOL_STR(module_layout), | |
1350 | mod, crc); | |
1351 | } | |
1352 | ||
1353 | /* First part is kernel version, which we ignore if module has crcs. */ | |
1354 | static inline int same_magic(const char *amagic, const char *bmagic, | |
1355 | bool has_crcs) | |
1356 | { | |
1357 | if (has_crcs) { | |
1358 | amagic += strcspn(amagic, " "); | |
1359 | bmagic += strcspn(bmagic, " "); | |
1360 | } | |
1361 | return strcmp(amagic, bmagic) == 0; | |
1362 | } | |
1363 | #else | |
1364 | static inline int check_version(const struct load_info *info, | |
1365 | const char *symname, | |
1366 | struct module *mod, | |
1367 | const s32 *crc) | |
1368 | { | |
1369 | return 1; | |
1370 | } | |
1371 | ||
1372 | static inline int check_modstruct_version(const struct load_info *info, | |
1373 | struct module *mod) | |
1374 | { | |
1375 | return 1; | |
1376 | } | |
1377 | ||
1378 | static inline int same_magic(const char *amagic, const char *bmagic, | |
1379 | bool has_crcs) | |
1380 | { | |
1381 | return strcmp(amagic, bmagic) == 0; | |
1382 | } | |
1383 | #endif /* CONFIG_MODVERSIONS */ | |
1384 | ||
1385 | /* Resolve a symbol for this module. I.e. if we find one, record usage. */ | |
1386 | static const struct kernel_symbol *resolve_symbol(struct module *mod, | |
1387 | const struct load_info *info, | |
1388 | const char *name, | |
1389 | char ownername[]) | |
1390 | { | |
1391 | struct module *owner; | |
1392 | const struct kernel_symbol *sym; | |
1393 | const s32 *crc; | |
1394 | int err; | |
1395 | ||
1396 | /* | |
1397 | * The module_mutex should not be a heavily contended lock; | |
1398 | * if we get the occasional sleep here, we'll go an extra iteration | |
1399 | * in the wait_event_interruptible(), which is harmless. | |
1400 | */ | |
1401 | sched_annotate_sleep(); | |
1402 | mutex_lock(&module_mutex); | |
1403 | sym = find_symbol(name, &owner, &crc, | |
1404 | !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); | |
1405 | if (!sym) | |
1406 | goto unlock; | |
1407 | ||
1408 | if (!check_version(info, name, mod, crc)) { | |
1409 | sym = ERR_PTR(-EINVAL); | |
1410 | goto getname; | |
1411 | } | |
1412 | ||
1413 | err = ref_module(mod, owner); | |
1414 | if (err) { | |
1415 | sym = ERR_PTR(err); | |
1416 | goto getname; | |
1417 | } | |
1418 | ||
1419 | getname: | |
1420 | /* We must make copy under the lock if we failed to get ref. */ | |
1421 | strncpy(ownername, module_name(owner), MODULE_NAME_LEN); | |
1422 | unlock: | |
1423 | mutex_unlock(&module_mutex); | |
1424 | return sym; | |
1425 | } | |
1426 | ||
1427 | static const struct kernel_symbol * | |
1428 | resolve_symbol_wait(struct module *mod, | |
1429 | const struct load_info *info, | |
1430 | const char *name) | |
1431 | { | |
1432 | const struct kernel_symbol *ksym; | |
1433 | char owner[MODULE_NAME_LEN]; | |
1434 | ||
1435 | if (wait_event_interruptible_timeout(module_wq, | |
1436 | !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) | |
1437 | || PTR_ERR(ksym) != -EBUSY, | |
1438 | 30 * HZ) <= 0) { | |
1439 | pr_warn("%s: gave up waiting for init of module %s.\n", | |
1440 | mod->name, owner); | |
1441 | } | |
1442 | return ksym; | |
1443 | } | |
1444 | ||
1445 | /* | |
1446 | * /sys/module/foo/sections stuff | |
1447 | * J. Corbet <corbet@lwn.net> | |
1448 | */ | |
1449 | #ifdef CONFIG_SYSFS | |
1450 | ||
1451 | #ifdef CONFIG_KALLSYMS | |
1452 | static inline bool sect_empty(const Elf_Shdr *sect) | |
1453 | { | |
1454 | return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; | |
1455 | } | |
1456 | ||
1457 | struct module_sect_attr { | |
1458 | struct module_attribute mattr; | |
1459 | char *name; | |
1460 | unsigned long address; | |
1461 | }; | |
1462 | ||
1463 | struct module_sect_attrs { | |
1464 | struct attribute_group grp; | |
1465 | unsigned int nsections; | |
1466 | struct module_sect_attr attrs[0]; | |
1467 | }; | |
1468 | ||
1469 | static ssize_t module_sect_show(struct module_attribute *mattr, | |
1470 | struct module_kobject *mk, char *buf) | |
1471 | { | |
1472 | struct module_sect_attr *sattr = | |
1473 | container_of(mattr, struct module_sect_attr, mattr); | |
1474 | return sprintf(buf, "0x%px\n", kptr_restrict < 2 ? | |
1475 | (void *)sattr->address : NULL); | |
1476 | } | |
1477 | ||
1478 | static void free_sect_attrs(struct module_sect_attrs *sect_attrs) | |
1479 | { | |
1480 | unsigned int section; | |
1481 | ||
1482 | for (section = 0; section < sect_attrs->nsections; section++) | |
1483 | kfree(sect_attrs->attrs[section].name); | |
1484 | kfree(sect_attrs); | |
1485 | } | |
1486 | ||
1487 | static void add_sect_attrs(struct module *mod, const struct load_info *info) | |
1488 | { | |
1489 | unsigned int nloaded = 0, i, size[2]; | |
1490 | struct module_sect_attrs *sect_attrs; | |
1491 | struct module_sect_attr *sattr; | |
1492 | struct attribute **gattr; | |
1493 | ||
1494 | /* Count loaded sections and allocate structures */ | |
1495 | for (i = 0; i < info->hdr->e_shnum; i++) | |
1496 | if (!sect_empty(&info->sechdrs[i])) | |
1497 | nloaded++; | |
1498 | size[0] = ALIGN(sizeof(*sect_attrs) | |
1499 | + nloaded * sizeof(sect_attrs->attrs[0]), | |
1500 | sizeof(sect_attrs->grp.attrs[0])); | |
1501 | size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]); | |
1502 | sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); | |
1503 | if (sect_attrs == NULL) | |
1504 | return; | |
1505 | ||
1506 | /* Setup section attributes. */ | |
1507 | sect_attrs->grp.name = "sections"; | |
1508 | sect_attrs->grp.attrs = (void *)sect_attrs + size[0]; | |
1509 | ||
1510 | sect_attrs->nsections = 0; | |
1511 | sattr = §_attrs->attrs[0]; | |
1512 | gattr = §_attrs->grp.attrs[0]; | |
1513 | for (i = 0; i < info->hdr->e_shnum; i++) { | |
1514 | Elf_Shdr *sec = &info->sechdrs[i]; | |
1515 | if (sect_empty(sec)) | |
1516 | continue; | |
1517 | sattr->address = sec->sh_addr; | |
1518 | sattr->name = kstrdup(info->secstrings + sec->sh_name, | |
1519 | GFP_KERNEL); | |
1520 | if (sattr->name == NULL) | |
1521 | goto out; | |
1522 | sect_attrs->nsections++; | |
1523 | sysfs_attr_init(&sattr->mattr.attr); | |
1524 | sattr->mattr.show = module_sect_show; | |
1525 | sattr->mattr.store = NULL; | |
1526 | sattr->mattr.attr.name = sattr->name; | |
1527 | sattr->mattr.attr.mode = S_IRUSR; | |
1528 | *(gattr++) = &(sattr++)->mattr.attr; | |
1529 | } | |
1530 | *gattr = NULL; | |
1531 | ||
1532 | if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) | |
1533 | goto out; | |
1534 | ||
1535 | mod->sect_attrs = sect_attrs; | |
1536 | return; | |
1537 | out: | |
1538 | free_sect_attrs(sect_attrs); | |
1539 | } | |
1540 | ||
1541 | static void remove_sect_attrs(struct module *mod) | |
1542 | { | |
1543 | if (mod->sect_attrs) { | |
1544 | sysfs_remove_group(&mod->mkobj.kobj, | |
1545 | &mod->sect_attrs->grp); | |
1546 | /* We are positive that no one is using any sect attrs | |
1547 | * at this point. Deallocate immediately. */ | |
1548 | free_sect_attrs(mod->sect_attrs); | |
1549 | mod->sect_attrs = NULL; | |
1550 | } | |
1551 | } | |
1552 | ||
1553 | /* | |
1554 | * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. | |
1555 | */ | |
1556 | ||
1557 | struct module_notes_attrs { | |
1558 | struct kobject *dir; | |
1559 | unsigned int notes; | |
1560 | struct bin_attribute attrs[0]; | |
1561 | }; | |
1562 | ||
1563 | static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, | |
1564 | struct bin_attribute *bin_attr, | |
1565 | char *buf, loff_t pos, size_t count) | |
1566 | { | |
1567 | /* | |
1568 | * The caller checked the pos and count against our size. | |
1569 | */ | |
1570 | memcpy(buf, bin_attr->private + pos, count); | |
1571 | return count; | |
1572 | } | |
1573 | ||
1574 | static void free_notes_attrs(struct module_notes_attrs *notes_attrs, | |
1575 | unsigned int i) | |
1576 | { | |
1577 | if (notes_attrs->dir) { | |
1578 | while (i-- > 0) | |
1579 | sysfs_remove_bin_file(notes_attrs->dir, | |
1580 | ¬es_attrs->attrs[i]); | |
1581 | kobject_put(notes_attrs->dir); | |
1582 | } | |
1583 | kfree(notes_attrs); | |
1584 | } | |
1585 | ||
1586 | static void add_notes_attrs(struct module *mod, const struct load_info *info) | |
1587 | { | |
1588 | unsigned int notes, loaded, i; | |
1589 | struct module_notes_attrs *notes_attrs; | |
1590 | struct bin_attribute *nattr; | |
1591 | ||
1592 | /* failed to create section attributes, so can't create notes */ | |
1593 | if (!mod->sect_attrs) | |
1594 | return; | |
1595 | ||
1596 | /* Count notes sections and allocate structures. */ | |
1597 | notes = 0; | |
1598 | for (i = 0; i < info->hdr->e_shnum; i++) | |
1599 | if (!sect_empty(&info->sechdrs[i]) && | |
1600 | (info->sechdrs[i].sh_type == SHT_NOTE)) | |
1601 | ++notes; | |
1602 | ||
1603 | if (notes == 0) | |
1604 | return; | |
1605 | ||
1606 | notes_attrs = kzalloc(sizeof(*notes_attrs) | |
1607 | + notes * sizeof(notes_attrs->attrs[0]), | |
1608 | GFP_KERNEL); | |
1609 | if (notes_attrs == NULL) | |
1610 | return; | |
1611 | ||
1612 | notes_attrs->notes = notes; | |
1613 | nattr = ¬es_attrs->attrs[0]; | |
1614 | for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { | |
1615 | if (sect_empty(&info->sechdrs[i])) | |
1616 | continue; | |
1617 | if (info->sechdrs[i].sh_type == SHT_NOTE) { | |
1618 | sysfs_bin_attr_init(nattr); | |
1619 | nattr->attr.name = mod->sect_attrs->attrs[loaded].name; | |
1620 | nattr->attr.mode = S_IRUGO; | |
1621 | nattr->size = info->sechdrs[i].sh_size; | |
1622 | nattr->private = (void *) info->sechdrs[i].sh_addr; | |
1623 | nattr->read = module_notes_read; | |
1624 | ++nattr; | |
1625 | } | |
1626 | ++loaded; | |
1627 | } | |
1628 | ||
1629 | notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); | |
1630 | if (!notes_attrs->dir) | |
1631 | goto out; | |
1632 | ||
1633 | for (i = 0; i < notes; ++i) | |
1634 | if (sysfs_create_bin_file(notes_attrs->dir, | |
1635 | ¬es_attrs->attrs[i])) | |
1636 | goto out; | |
1637 | ||
1638 | mod->notes_attrs = notes_attrs; | |
1639 | return; | |
1640 | ||
1641 | out: | |
1642 | free_notes_attrs(notes_attrs, i); | |
1643 | } | |
1644 | ||
1645 | static void remove_notes_attrs(struct module *mod) | |
1646 | { | |
1647 | if (mod->notes_attrs) | |
1648 | free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); | |
1649 | } | |
1650 | ||
1651 | #else | |
1652 | ||
1653 | static inline void add_sect_attrs(struct module *mod, | |
1654 | const struct load_info *info) | |
1655 | { | |
1656 | } | |
1657 | ||
1658 | static inline void remove_sect_attrs(struct module *mod) | |
1659 | { | |
1660 | } | |
1661 | ||
1662 | static inline void add_notes_attrs(struct module *mod, | |
1663 | const struct load_info *info) | |
1664 | { | |
1665 | } | |
1666 | ||
1667 | static inline void remove_notes_attrs(struct module *mod) | |
1668 | { | |
1669 | } | |
1670 | #endif /* CONFIG_KALLSYMS */ | |
1671 | ||
1672 | static void del_usage_links(struct module *mod) | |
1673 | { | |
1674 | #ifdef CONFIG_MODULE_UNLOAD | |
1675 | struct module_use *use; | |
1676 | ||
1677 | mutex_lock(&module_mutex); | |
1678 | list_for_each_entry(use, &mod->target_list, target_list) | |
1679 | sysfs_remove_link(use->target->holders_dir, mod->name); | |
1680 | mutex_unlock(&module_mutex); | |
1681 | #endif | |
1682 | } | |
1683 | ||
1684 | static int add_usage_links(struct module *mod) | |
1685 | { | |
1686 | int ret = 0; | |
1687 | #ifdef CONFIG_MODULE_UNLOAD | |
1688 | struct module_use *use; | |
1689 | ||
1690 | mutex_lock(&module_mutex); | |
1691 | list_for_each_entry(use, &mod->target_list, target_list) { | |
1692 | ret = sysfs_create_link(use->target->holders_dir, | |
1693 | &mod->mkobj.kobj, mod->name); | |
1694 | if (ret) | |
1695 | break; | |
1696 | } | |
1697 | mutex_unlock(&module_mutex); | |
1698 | if (ret) | |
1699 | del_usage_links(mod); | |
1700 | #endif | |
1701 | return ret; | |
1702 | } | |
1703 | ||
1704 | static void module_remove_modinfo_attrs(struct module *mod, int end); | |
1705 | ||
1706 | static int module_add_modinfo_attrs(struct module *mod) | |
1707 | { | |
1708 | struct module_attribute *attr; | |
1709 | struct module_attribute *temp_attr; | |
1710 | int error = 0; | |
1711 | int i; | |
1712 | ||
1713 | mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * | |
1714 | (ARRAY_SIZE(modinfo_attrs) + 1)), | |
1715 | GFP_KERNEL); | |
1716 | if (!mod->modinfo_attrs) | |
1717 | return -ENOMEM; | |
1718 | ||
1719 | temp_attr = mod->modinfo_attrs; | |
1720 | for (i = 0; (attr = modinfo_attrs[i]); i++) { | |
1721 | if (!attr->test || attr->test(mod)) { | |
1722 | memcpy(temp_attr, attr, sizeof(*temp_attr)); | |
1723 | sysfs_attr_init(&temp_attr->attr); | |
1724 | error = sysfs_create_file(&mod->mkobj.kobj, | |
1725 | &temp_attr->attr); | |
1726 | if (error) | |
1727 | goto error_out; | |
1728 | ++temp_attr; | |
1729 | } | |
1730 | } | |
1731 | ||
1732 | return 0; | |
1733 | ||
1734 | error_out: | |
1735 | if (i > 0) | |
1736 | module_remove_modinfo_attrs(mod, --i); | |
1737 | else | |
1738 | kfree(mod->modinfo_attrs); | |
1739 | return error; | |
1740 | } | |
1741 | ||
1742 | static void module_remove_modinfo_attrs(struct module *mod, int end) | |
1743 | { | |
1744 | struct module_attribute *attr; | |
1745 | int i; | |
1746 | ||
1747 | for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { | |
1748 | if (end >= 0 && i > end) | |
1749 | break; | |
1750 | /* pick a field to test for end of list */ | |
1751 | if (!attr->attr.name) | |
1752 | break; | |
1753 | sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); | |
1754 | if (attr->free) | |
1755 | attr->free(mod); | |
1756 | } | |
1757 | kfree(mod->modinfo_attrs); | |
1758 | } | |
1759 | ||
1760 | static void mod_kobject_put(struct module *mod) | |
1761 | { | |
1762 | DECLARE_COMPLETION_ONSTACK(c); | |
1763 | mod->mkobj.kobj_completion = &c; | |
1764 | kobject_put(&mod->mkobj.kobj); | |
1765 | wait_for_completion(&c); | |
1766 | } | |
1767 | ||
1768 | static int mod_sysfs_init(struct module *mod) | |
1769 | { | |
1770 | int err; | |
1771 | struct kobject *kobj; | |
1772 | ||
1773 | if (!module_sysfs_initialized) { | |
1774 | pr_err("%s: module sysfs not initialized\n", mod->name); | |
1775 | err = -EINVAL; | |
1776 | goto out; | |
1777 | } | |
1778 | ||
1779 | kobj = kset_find_obj(module_kset, mod->name); | |
1780 | if (kobj) { | |
1781 | pr_err("%s: module is already loaded\n", mod->name); | |
1782 | kobject_put(kobj); | |
1783 | err = -EINVAL; | |
1784 | goto out; | |
1785 | } | |
1786 | ||
1787 | mod->mkobj.mod = mod; | |
1788 | ||
1789 | memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); | |
1790 | mod->mkobj.kobj.kset = module_kset; | |
1791 | err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, | |
1792 | "%s", mod->name); | |
1793 | if (err) | |
1794 | mod_kobject_put(mod); | |
1795 | ||
1796 | /* delay uevent until full sysfs population */ | |
1797 | out: | |
1798 | return err; | |
1799 | } | |
1800 | ||
1801 | static int mod_sysfs_setup(struct module *mod, | |
1802 | const struct load_info *info, | |
1803 | struct kernel_param *kparam, | |
1804 | unsigned int num_params) | |
1805 | { | |
1806 | int err; | |
1807 | ||
1808 | err = mod_sysfs_init(mod); | |
1809 | if (err) | |
1810 | goto out; | |
1811 | ||
1812 | mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); | |
1813 | if (!mod->holders_dir) { | |
1814 | err = -ENOMEM; | |
1815 | goto out_unreg; | |
1816 | } | |
1817 | ||
1818 | err = module_param_sysfs_setup(mod, kparam, num_params); | |
1819 | if (err) | |
1820 | goto out_unreg_holders; | |
1821 | ||
1822 | err = module_add_modinfo_attrs(mod); | |
1823 | if (err) | |
1824 | goto out_unreg_param; | |
1825 | ||
1826 | err = add_usage_links(mod); | |
1827 | if (err) | |
1828 | goto out_unreg_modinfo_attrs; | |
1829 | ||
1830 | add_sect_attrs(mod, info); | |
1831 | add_notes_attrs(mod, info); | |
1832 | ||
1833 | kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); | |
1834 | return 0; | |
1835 | ||
1836 | out_unreg_modinfo_attrs: | |
1837 | module_remove_modinfo_attrs(mod, -1); | |
1838 | out_unreg_param: | |
1839 | module_param_sysfs_remove(mod); | |
1840 | out_unreg_holders: | |
1841 | kobject_put(mod->holders_dir); | |
1842 | out_unreg: | |
1843 | mod_kobject_put(mod); | |
1844 | out: | |
1845 | return err; | |
1846 | } | |
1847 | ||
1848 | static void mod_sysfs_fini(struct module *mod) | |
1849 | { | |
1850 | remove_notes_attrs(mod); | |
1851 | remove_sect_attrs(mod); | |
1852 | mod_kobject_put(mod); | |
1853 | } | |
1854 | ||
1855 | static void init_param_lock(struct module *mod) | |
1856 | { | |
1857 | mutex_init(&mod->param_lock); | |
1858 | } | |
1859 | #else /* !CONFIG_SYSFS */ | |
1860 | ||
1861 | static int mod_sysfs_setup(struct module *mod, | |
1862 | const struct load_info *info, | |
1863 | struct kernel_param *kparam, | |
1864 | unsigned int num_params) | |
1865 | { | |
1866 | return 0; | |
1867 | } | |
1868 | ||
1869 | static void mod_sysfs_fini(struct module *mod) | |
1870 | { | |
1871 | } | |
1872 | ||
1873 | static void module_remove_modinfo_attrs(struct module *mod, int end) | |
1874 | { | |
1875 | } | |
1876 | ||
1877 | static void del_usage_links(struct module *mod) | |
1878 | { | |
1879 | } | |
1880 | ||
1881 | static void init_param_lock(struct module *mod) | |
1882 | { | |
1883 | } | |
1884 | #endif /* CONFIG_SYSFS */ | |
1885 | ||
1886 | static void mod_sysfs_teardown(struct module *mod) | |
1887 | { | |
1888 | del_usage_links(mod); | |
1889 | module_remove_modinfo_attrs(mod, -1); | |
1890 | module_param_sysfs_remove(mod); | |
1891 | kobject_put(mod->mkobj.drivers_dir); | |
1892 | kobject_put(mod->holders_dir); | |
1893 | mod_sysfs_fini(mod); | |
1894 | } | |
1895 | ||
1896 | #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX | |
1897 | /* | |
1898 | * LKM RO/NX protection: protect module's text/ro-data | |
1899 | * from modification and any data from execution. | |
1900 | * | |
1901 | * General layout of module is: | |
1902 | * [text] [read-only-data] [ro-after-init] [writable data] | |
1903 | * text_size -----^ ^ ^ ^ | |
1904 | * ro_size ------------------------| | | | |
1905 | * ro_after_init_size -----------------------------| | | |
1906 | * size -----------------------------------------------------------| | |
1907 | * | |
1908 | * These values are always page-aligned (as is base) | |
1909 | */ | |
1910 | static void frob_text(const struct module_layout *layout, | |
1911 | int (*set_memory)(unsigned long start, int num_pages)) | |
1912 | { | |
1913 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); | |
1914 | BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); | |
1915 | set_memory((unsigned long)layout->base, | |
1916 | layout->text_size >> PAGE_SHIFT); | |
1917 | } | |
1918 | ||
1919 | #ifdef CONFIG_STRICT_MODULE_RWX | |
1920 | static void frob_rodata(const struct module_layout *layout, | |
1921 | int (*set_memory)(unsigned long start, int num_pages)) | |
1922 | { | |
1923 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); | |
1924 | BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); | |
1925 | BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); | |
1926 | set_memory((unsigned long)layout->base + layout->text_size, | |
1927 | (layout->ro_size - layout->text_size) >> PAGE_SHIFT); | |
1928 | } | |
1929 | ||
1930 | static void frob_ro_after_init(const struct module_layout *layout, | |
1931 | int (*set_memory)(unsigned long start, int num_pages)) | |
1932 | { | |
1933 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); | |
1934 | BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); | |
1935 | BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); | |
1936 | set_memory((unsigned long)layout->base + layout->ro_size, | |
1937 | (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT); | |
1938 | } | |
1939 | ||
1940 | static void frob_writable_data(const struct module_layout *layout, | |
1941 | int (*set_memory)(unsigned long start, int num_pages)) | |
1942 | { | |
1943 | BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); | |
1944 | BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); | |
1945 | BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1)); | |
1946 | set_memory((unsigned long)layout->base + layout->ro_after_init_size, | |
1947 | (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); | |
1948 | } | |
1949 | ||
1950 | /* livepatching wants to disable read-only so it can frob module. */ | |
1951 | void module_disable_ro(const struct module *mod) | |
1952 | { | |
1953 | if (!rodata_enabled) | |
1954 | return; | |
1955 | ||
1956 | frob_text(&mod->core_layout, set_memory_rw); | |
1957 | frob_rodata(&mod->core_layout, set_memory_rw); | |
1958 | frob_ro_after_init(&mod->core_layout, set_memory_rw); | |
1959 | frob_text(&mod->init_layout, set_memory_rw); | |
1960 | frob_rodata(&mod->init_layout, set_memory_rw); | |
1961 | } | |
1962 | ||
1963 | void module_enable_ro(const struct module *mod, bool after_init) | |
1964 | { | |
1965 | if (!rodata_enabled) | |
1966 | return; | |
1967 | ||
1968 | frob_text(&mod->core_layout, set_memory_ro); | |
1969 | ||
1970 | frob_rodata(&mod->core_layout, set_memory_ro); | |
1971 | frob_text(&mod->init_layout, set_memory_ro); | |
1972 | frob_rodata(&mod->init_layout, set_memory_ro); | |
1973 | ||
1974 | if (after_init) | |
1975 | frob_ro_after_init(&mod->core_layout, set_memory_ro); | |
1976 | } | |
1977 | ||
1978 | static void module_enable_nx(const struct module *mod) | |
1979 | { | |
1980 | frob_rodata(&mod->core_layout, set_memory_nx); | |
1981 | frob_ro_after_init(&mod->core_layout, set_memory_nx); | |
1982 | frob_writable_data(&mod->core_layout, set_memory_nx); | |
1983 | frob_rodata(&mod->init_layout, set_memory_nx); | |
1984 | frob_writable_data(&mod->init_layout, set_memory_nx); | |
1985 | } | |
1986 | ||
1987 | static void module_disable_nx(const struct module *mod) | |
1988 | { | |
1989 | frob_rodata(&mod->core_layout, set_memory_x); | |
1990 | frob_ro_after_init(&mod->core_layout, set_memory_x); | |
1991 | frob_writable_data(&mod->core_layout, set_memory_x); | |
1992 | frob_rodata(&mod->init_layout, set_memory_x); | |
1993 | frob_writable_data(&mod->init_layout, set_memory_x); | |
1994 | } | |
1995 | ||
1996 | /* Iterate through all modules and set each module's text as RW */ | |
1997 | void set_all_modules_text_rw(void) | |
1998 | { | |
1999 | struct module *mod; | |
2000 | ||
2001 | if (!rodata_enabled) | |
2002 | return; | |
2003 | ||
2004 | mutex_lock(&module_mutex); | |
2005 | list_for_each_entry_rcu(mod, &modules, list) { | |
2006 | if (mod->state == MODULE_STATE_UNFORMED) | |
2007 | continue; | |
2008 | ||
2009 | frob_text(&mod->core_layout, set_memory_rw); | |
2010 | frob_text(&mod->init_layout, set_memory_rw); | |
2011 | } | |
2012 | mutex_unlock(&module_mutex); | |
2013 | } | |
2014 | ||
2015 | /* Iterate through all modules and set each module's text as RO */ | |
2016 | void set_all_modules_text_ro(void) | |
2017 | { | |
2018 | struct module *mod; | |
2019 | ||
2020 | if (!rodata_enabled) | |
2021 | return; | |
2022 | ||
2023 | mutex_lock(&module_mutex); | |
2024 | list_for_each_entry_rcu(mod, &modules, list) { | |
2025 | /* | |
2026 | * Ignore going modules since it's possible that ro | |
2027 | * protection has already been disabled, otherwise we'll | |
2028 | * run into protection faults at module deallocation. | |
2029 | */ | |
2030 | if (mod->state == MODULE_STATE_UNFORMED || | |
2031 | mod->state == MODULE_STATE_GOING) | |
2032 | continue; | |
2033 | ||
2034 | frob_text(&mod->core_layout, set_memory_ro); | |
2035 | frob_text(&mod->init_layout, set_memory_ro); | |
2036 | } | |
2037 | mutex_unlock(&module_mutex); | |
2038 | } | |
2039 | ||
2040 | static void disable_ro_nx(const struct module_layout *layout) | |
2041 | { | |
2042 | if (rodata_enabled) { | |
2043 | frob_text(layout, set_memory_rw); | |
2044 | frob_rodata(layout, set_memory_rw); | |
2045 | frob_ro_after_init(layout, set_memory_rw); | |
2046 | } | |
2047 | frob_rodata(layout, set_memory_x); | |
2048 | frob_ro_after_init(layout, set_memory_x); | |
2049 | frob_writable_data(layout, set_memory_x); | |
2050 | } | |
2051 | ||
2052 | #else /* !CONFIG_STRICT_MODULE_RWX */ | |
2053 | static void disable_ro_nx(const struct module_layout *layout) { } | |
2054 | static void module_enable_nx(const struct module *mod) { } | |
2055 | static void module_disable_nx(const struct module *mod) { } | |
2056 | #endif /* CONFIG_STRICT_MODULE_RWX */ | |
2057 | ||
2058 | static void module_enable_x(const struct module *mod) | |
2059 | { | |
2060 | frob_text(&mod->core_layout, set_memory_x); | |
2061 | frob_text(&mod->init_layout, set_memory_x); | |
2062 | } | |
2063 | #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ | |
2064 | static void disable_ro_nx(const struct module_layout *layout) { } | |
2065 | static void module_enable_nx(const struct module *mod) { } | |
2066 | static void module_disable_nx(const struct module *mod) { } | |
2067 | static void module_enable_x(const struct module *mod) { } | |
2068 | #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ | |
2069 | ||
2070 | #ifdef CONFIG_LIVEPATCH | |
2071 | /* | |
2072 | * Persist Elf information about a module. Copy the Elf header, | |
2073 | * section header table, section string table, and symtab section | |
2074 | * index from info to mod->klp_info. | |
2075 | */ | |
2076 | static int copy_module_elf(struct module *mod, struct load_info *info) | |
2077 | { | |
2078 | unsigned int size, symndx; | |
2079 | int ret; | |
2080 | ||
2081 | size = sizeof(*mod->klp_info); | |
2082 | mod->klp_info = kmalloc(size, GFP_KERNEL); | |
2083 | if (mod->klp_info == NULL) | |
2084 | return -ENOMEM; | |
2085 | ||
2086 | /* Elf header */ | |
2087 | size = sizeof(mod->klp_info->hdr); | |
2088 | memcpy(&mod->klp_info->hdr, info->hdr, size); | |
2089 | ||
2090 | /* Elf section header table */ | |
2091 | size = sizeof(*info->sechdrs) * info->hdr->e_shnum; | |
2092 | mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL); | |
2093 | if (mod->klp_info->sechdrs == NULL) { | |
2094 | ret = -ENOMEM; | |
2095 | goto free_info; | |
2096 | } | |
2097 | memcpy(mod->klp_info->sechdrs, info->sechdrs, size); | |
2098 | ||
2099 | /* Elf section name string table */ | |
2100 | size = info->sechdrs[info->hdr->e_shstrndx].sh_size; | |
2101 | mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL); | |
2102 | if (mod->klp_info->secstrings == NULL) { | |
2103 | ret = -ENOMEM; | |
2104 | goto free_sechdrs; | |
2105 | } | |
2106 | memcpy(mod->klp_info->secstrings, info->secstrings, size); | |
2107 | ||
2108 | /* Elf symbol section index */ | |
2109 | symndx = info->index.sym; | |
2110 | mod->klp_info->symndx = symndx; | |
2111 | ||
2112 | /* | |
2113 | * For livepatch modules, core_kallsyms.symtab is a complete | |
2114 | * copy of the original symbol table. Adjust sh_addr to point | |
2115 | * to core_kallsyms.symtab since the copy of the symtab in module | |
2116 | * init memory is freed at the end of do_init_module(). | |
2117 | */ | |
2118 | mod->klp_info->sechdrs[symndx].sh_addr = \ | |
2119 | (unsigned long) mod->core_kallsyms.symtab; | |
2120 | ||
2121 | return 0; | |
2122 | ||
2123 | free_sechdrs: | |
2124 | kfree(mod->klp_info->sechdrs); | |
2125 | free_info: | |
2126 | kfree(mod->klp_info); | |
2127 | return ret; | |
2128 | } | |
2129 | ||
2130 | static void free_module_elf(struct module *mod) | |
2131 | { | |
2132 | kfree(mod->klp_info->sechdrs); | |
2133 | kfree(mod->klp_info->secstrings); | |
2134 | kfree(mod->klp_info); | |
2135 | } | |
2136 | #else /* !CONFIG_LIVEPATCH */ | |
2137 | static int copy_module_elf(struct module *mod, struct load_info *info) | |
2138 | { | |
2139 | return 0; | |
2140 | } | |
2141 | ||
2142 | static void free_module_elf(struct module *mod) | |
2143 | { | |
2144 | } | |
2145 | #endif /* CONFIG_LIVEPATCH */ | |
2146 | ||
2147 | void __weak module_memfree(void *module_region) | |
2148 | { | |
2149 | vfree(module_region); | |
2150 | } | |
2151 | ||
2152 | void __weak module_arch_cleanup(struct module *mod) | |
2153 | { | |
2154 | } | |
2155 | ||
2156 | void __weak module_arch_freeing_init(struct module *mod) | |
2157 | { | |
2158 | } | |
2159 | ||
2160 | /* Free a module, remove from lists, etc. */ | |
2161 | static void free_module(struct module *mod) | |
2162 | { | |
2163 | trace_module_free(mod); | |
2164 | ||
2165 | mod_sysfs_teardown(mod); | |
2166 | ||
2167 | /* We leave it in list to prevent duplicate loads, but make sure | |
2168 | * that noone uses it while it's being deconstructed. */ | |
2169 | mutex_lock(&module_mutex); | |
2170 | mod->state = MODULE_STATE_UNFORMED; | |
2171 | mutex_unlock(&module_mutex); | |
2172 | ||
2173 | /* Remove dynamic debug info */ | |
2174 | ddebug_remove_module(mod->name); | |
2175 | ||
2176 | /* Arch-specific cleanup. */ | |
2177 | module_arch_cleanup(mod); | |
2178 | ||
2179 | /* Module unload stuff */ | |
2180 | module_unload_free(mod); | |
2181 | ||
2182 | /* Free any allocated parameters. */ | |
2183 | destroy_params(mod->kp, mod->num_kp); | |
2184 | ||
2185 | if (is_livepatch_module(mod)) | |
2186 | free_module_elf(mod); | |
2187 | ||
2188 | /* Now we can delete it from the lists */ | |
2189 | mutex_lock(&module_mutex); | |
2190 | /* Unlink carefully: kallsyms could be walking list. */ | |
2191 | list_del_rcu(&mod->list); | |
2192 | mod_tree_remove(mod); | |
2193 | /* Remove this module from bug list, this uses list_del_rcu */ | |
2194 | module_bug_cleanup(mod); | |
2195 | /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */ | |
2196 | synchronize_sched(); | |
2197 | mutex_unlock(&module_mutex); | |
2198 | ||
2199 | /* This may be empty, but that's OK */ | |
2200 | disable_ro_nx(&mod->init_layout); | |
2201 | module_arch_freeing_init(mod); | |
2202 | module_memfree(mod->init_layout.base); | |
2203 | kfree(mod->args); | |
2204 | percpu_modfree(mod); | |
2205 | ||
2206 | /* Free lock-classes; relies on the preceding sync_rcu(). */ | |
2207 | lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); | |
2208 | ||
2209 | /* Finally, free the core (containing the module structure) */ | |
2210 | disable_ro_nx(&mod->core_layout); | |
2211 | module_memfree(mod->core_layout.base); | |
2212 | ||
2213 | #ifdef CONFIG_MPU | |
2214 | update_protections(current->mm); | |
2215 | #endif | |
2216 | } | |
2217 | ||
2218 | void *__symbol_get(const char *symbol) | |
2219 | { | |
2220 | struct module *owner; | |
2221 | const struct kernel_symbol *sym; | |
2222 | ||
2223 | preempt_disable(); | |
2224 | sym = find_symbol(symbol, &owner, NULL, true, true); | |
2225 | if (sym && strong_try_module_get(owner)) | |
2226 | sym = NULL; | |
2227 | preempt_enable(); | |
2228 | ||
2229 | return sym ? (void *)sym->value : NULL; | |
2230 | } | |
2231 | EXPORT_SYMBOL_GPL(__symbol_get); | |
2232 | ||
2233 | /* | |
2234 | * Ensure that an exported symbol [global namespace] does not already exist | |
2235 | * in the kernel or in some other module's exported symbol table. | |
2236 | * | |
2237 | * You must hold the module_mutex. | |
2238 | */ | |
2239 | static int verify_export_symbols(struct module *mod) | |
2240 | { | |
2241 | unsigned int i; | |
2242 | struct module *owner; | |
2243 | const struct kernel_symbol *s; | |
2244 | struct { | |
2245 | const struct kernel_symbol *sym; | |
2246 | unsigned int num; | |
2247 | } arr[] = { | |
2248 | { mod->syms, mod->num_syms }, | |
2249 | { mod->gpl_syms, mod->num_gpl_syms }, | |
2250 | { mod->gpl_future_syms, mod->num_gpl_future_syms }, | |
2251 | #ifdef CONFIG_UNUSED_SYMBOLS | |
2252 | { mod->unused_syms, mod->num_unused_syms }, | |
2253 | { mod->unused_gpl_syms, mod->num_unused_gpl_syms }, | |
2254 | #endif | |
2255 | }; | |
2256 | ||
2257 | for (i = 0; i < ARRAY_SIZE(arr); i++) { | |
2258 | for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { | |
2259 | if (find_symbol(s->name, &owner, NULL, true, false)) { | |
2260 | pr_err("%s: exports duplicate symbol %s" | |
2261 | " (owned by %s)\n", | |
2262 | mod->name, s->name, module_name(owner)); | |
2263 | return -ENOEXEC; | |
2264 | } | |
2265 | } | |
2266 | } | |
2267 | return 0; | |
2268 | } | |
2269 | ||
2270 | /* Change all symbols so that st_value encodes the pointer directly. */ | |
2271 | static int simplify_symbols(struct module *mod, const struct load_info *info) | |
2272 | { | |
2273 | Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; | |
2274 | Elf_Sym *sym = (void *)symsec->sh_addr; | |
2275 | unsigned long secbase; | |
2276 | unsigned int i; | |
2277 | int ret = 0; | |
2278 | const struct kernel_symbol *ksym; | |
2279 | ||
2280 | for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { | |
2281 | const char *name = info->strtab + sym[i].st_name; | |
2282 | ||
2283 | switch (sym[i].st_shndx) { | |
2284 | case SHN_COMMON: | |
2285 | /* Ignore common symbols */ | |
2286 | if (!strncmp(name, "__gnu_lto", 9)) | |
2287 | break; | |
2288 | ||
2289 | /* We compiled with -fno-common. These are not | |
2290 | supposed to happen. */ | |
2291 | pr_debug("Common symbol: %s\n", name); | |
2292 | pr_warn("%s: please compile with -fno-common\n", | |
2293 | mod->name); | |
2294 | ret = -ENOEXEC; | |
2295 | break; | |
2296 | ||
2297 | case SHN_ABS: | |
2298 | /* Don't need to do anything */ | |
2299 | pr_debug("Absolute symbol: 0x%08lx\n", | |
2300 | (long)sym[i].st_value); | |
2301 | break; | |
2302 | ||
2303 | case SHN_LIVEPATCH: | |
2304 | /* Livepatch symbols are resolved by livepatch */ | |
2305 | break; | |
2306 | ||
2307 | case SHN_UNDEF: | |
2308 | ksym = resolve_symbol_wait(mod, info, name); | |
2309 | /* Ok if resolved. */ | |
2310 | if (ksym && !IS_ERR(ksym)) { | |
2311 | sym[i].st_value = ksym->value; | |
2312 | break; | |
2313 | } | |
2314 | ||
2315 | /* Ok if weak. */ | |
2316 | if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK) | |
2317 | break; | |
2318 | ||
2319 | pr_warn("%s: Unknown symbol %s (err %li)\n", | |
2320 | mod->name, name, PTR_ERR(ksym)); | |
2321 | ret = PTR_ERR(ksym) ?: -ENOENT; | |
2322 | break; | |
2323 | ||
2324 | default: | |
2325 | /* Divert to percpu allocation if a percpu var. */ | |
2326 | if (sym[i].st_shndx == info->index.pcpu) | |
2327 | secbase = (unsigned long)mod_percpu(mod); | |
2328 | else | |
2329 | secbase = info->sechdrs[sym[i].st_shndx].sh_addr; | |
2330 | sym[i].st_value += secbase; | |
2331 | break; | |
2332 | } | |
2333 | } | |
2334 | ||
2335 | return ret; | |
2336 | } | |
2337 | ||
2338 | static int apply_relocations(struct module *mod, const struct load_info *info) | |
2339 | { | |
2340 | unsigned int i; | |
2341 | int err = 0; | |
2342 | ||
2343 | /* Now do relocations. */ | |
2344 | for (i = 1; i < info->hdr->e_shnum; i++) { | |
2345 | unsigned int infosec = info->sechdrs[i].sh_info; | |
2346 | ||
2347 | /* Not a valid relocation section? */ | |
2348 | if (infosec >= info->hdr->e_shnum) | |
2349 | continue; | |
2350 | ||
2351 | /* Don't bother with non-allocated sections */ | |
2352 | if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) | |
2353 | continue; | |
2354 | ||
2355 | /* Livepatch relocation sections are applied by livepatch */ | |
2356 | if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) | |
2357 | continue; | |
2358 | ||
2359 | if (info->sechdrs[i].sh_type == SHT_REL) | |
2360 | err = apply_relocate(info->sechdrs, info->strtab, | |
2361 | info->index.sym, i, mod); | |
2362 | else if (info->sechdrs[i].sh_type == SHT_RELA) | |
2363 | err = apply_relocate_add(info->sechdrs, info->strtab, | |
2364 | info->index.sym, i, mod); | |
2365 | if (err < 0) | |
2366 | break; | |
2367 | } | |
2368 | return err; | |
2369 | } | |
2370 | ||
2371 | /* Additional bytes needed by arch in front of individual sections */ | |
2372 | unsigned int __weak arch_mod_section_prepend(struct module *mod, | |
2373 | unsigned int section) | |
2374 | { | |
2375 | /* default implementation just returns zero */ | |
2376 | return 0; | |
2377 | } | |
2378 | ||
2379 | /* Update size with this section: return offset. */ | |
2380 | static long get_offset(struct module *mod, unsigned int *size, | |
2381 | Elf_Shdr *sechdr, unsigned int section) | |
2382 | { | |
2383 | long ret; | |
2384 | ||
2385 | *size += arch_mod_section_prepend(mod, section); | |
2386 | ret = ALIGN(*size, sechdr->sh_addralign ?: 1); | |
2387 | *size = ret + sechdr->sh_size; | |
2388 | return ret; | |
2389 | } | |
2390 | ||
2391 | /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld | |
2392 | might -- code, read-only data, read-write data, small data. Tally | |
2393 | sizes, and place the offsets into sh_entsize fields: high bit means it | |
2394 | belongs in init. */ | |
2395 | static void layout_sections(struct module *mod, struct load_info *info) | |
2396 | { | |
2397 | static unsigned long const masks[][2] = { | |
2398 | /* NOTE: all executable code must be the first section | |
2399 | * in this array; otherwise modify the text_size | |
2400 | * finder in the two loops below */ | |
2401 | { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, | |
2402 | { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, | |
2403 | { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, | |
2404 | { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, | |
2405 | { ARCH_SHF_SMALL | SHF_ALLOC, 0 } | |
2406 | }; | |
2407 | unsigned int m, i; | |
2408 | ||
2409 | for (i = 0; i < info->hdr->e_shnum; i++) | |
2410 | info->sechdrs[i].sh_entsize = ~0UL; | |
2411 | ||
2412 | pr_debug("Core section allocation order:\n"); | |
2413 | for (m = 0; m < ARRAY_SIZE(masks); ++m) { | |
2414 | for (i = 0; i < info->hdr->e_shnum; ++i) { | |
2415 | Elf_Shdr *s = &info->sechdrs[i]; | |
2416 | const char *sname = info->secstrings + s->sh_name; | |
2417 | ||
2418 | if ((s->sh_flags & masks[m][0]) != masks[m][0] | |
2419 | || (s->sh_flags & masks[m][1]) | |
2420 | || s->sh_entsize != ~0UL | |
2421 | || strstarts(sname, ".init")) | |
2422 | continue; | |
2423 | s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i); | |
2424 | pr_debug("\t%s\n", sname); | |
2425 | } | |
2426 | switch (m) { | |
2427 | case 0: /* executable */ | |
2428 | mod->core_layout.size = debug_align(mod->core_layout.size); | |
2429 | mod->core_layout.text_size = mod->core_layout.size; | |
2430 | break; | |
2431 | case 1: /* RO: text and ro-data */ | |
2432 | mod->core_layout.size = debug_align(mod->core_layout.size); | |
2433 | mod->core_layout.ro_size = mod->core_layout.size; | |
2434 | break; | |
2435 | case 2: /* RO after init */ | |
2436 | mod->core_layout.size = debug_align(mod->core_layout.size); | |
2437 | mod->core_layout.ro_after_init_size = mod->core_layout.size; | |
2438 | break; | |
2439 | case 4: /* whole core */ | |
2440 | mod->core_layout.size = debug_align(mod->core_layout.size); | |
2441 | break; | |
2442 | } | |
2443 | } | |
2444 | ||
2445 | pr_debug("Init section allocation order:\n"); | |
2446 | for (m = 0; m < ARRAY_SIZE(masks); ++m) { | |
2447 | for (i = 0; i < info->hdr->e_shnum; ++i) { | |
2448 | Elf_Shdr *s = &info->sechdrs[i]; | |
2449 | const char *sname = info->secstrings + s->sh_name; | |
2450 | ||
2451 | if ((s->sh_flags & masks[m][0]) != masks[m][0] | |
2452 | || (s->sh_flags & masks[m][1]) | |
2453 | || s->sh_entsize != ~0UL | |
2454 | || !strstarts(sname, ".init")) | |
2455 | continue; | |
2456 | s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i) | |
2457 | | INIT_OFFSET_MASK); | |
2458 | pr_debug("\t%s\n", sname); | |
2459 | } | |
2460 | switch (m) { | |
2461 | case 0: /* executable */ | |
2462 | mod->init_layout.size = debug_align(mod->init_layout.size); | |
2463 | mod->init_layout.text_size = mod->init_layout.size; | |
2464 | break; | |
2465 | case 1: /* RO: text and ro-data */ | |
2466 | mod->init_layout.size = debug_align(mod->init_layout.size); | |
2467 | mod->init_layout.ro_size = mod->init_layout.size; | |
2468 | break; | |
2469 | case 2: | |
2470 | /* | |
2471 | * RO after init doesn't apply to init_layout (only | |
2472 | * core_layout), so it just takes the value of ro_size. | |
2473 | */ | |
2474 | mod->init_layout.ro_after_init_size = mod->init_layout.ro_size; | |
2475 | break; | |
2476 | case 4: /* whole init */ | |
2477 | mod->init_layout.size = debug_align(mod->init_layout.size); | |
2478 | break; | |
2479 | } | |
2480 | } | |
2481 | } | |
2482 | ||
2483 | static void set_license(struct module *mod, const char *license) | |
2484 | { | |
2485 | if (!license) | |
2486 | license = "unspecified"; | |
2487 | ||
2488 | if (!license_is_gpl_compatible(license)) { | |
2489 | if (!test_taint(TAINT_PROPRIETARY_MODULE)) | |
2490 | pr_warn("%s: module license '%s' taints kernel.\n", | |
2491 | mod->name, license); | |
2492 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE, | |
2493 | LOCKDEP_NOW_UNRELIABLE); | |
2494 | } | |
2495 | } | |
2496 | ||
2497 | /* Parse tag=value strings from .modinfo section */ | |
2498 | static char *next_string(char *string, unsigned long *secsize) | |
2499 | { | |
2500 | /* Skip non-zero chars */ | |
2501 | while (string[0]) { | |
2502 | string++; | |
2503 | if ((*secsize)-- <= 1) | |
2504 | return NULL; | |
2505 | } | |
2506 | ||
2507 | /* Skip any zero padding. */ | |
2508 | while (!string[0]) { | |
2509 | string++; | |
2510 | if ((*secsize)-- <= 1) | |
2511 | return NULL; | |
2512 | } | |
2513 | return string; | |
2514 | } | |
2515 | ||
2516 | static char *get_modinfo(struct load_info *info, const char *tag) | |
2517 | { | |
2518 | char *p; | |
2519 | unsigned int taglen = strlen(tag); | |
2520 | Elf_Shdr *infosec = &info->sechdrs[info->index.info]; | |
2521 | unsigned long size = infosec->sh_size; | |
2522 | ||
2523 | for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) { | |
2524 | if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') | |
2525 | return p + taglen + 1; | |
2526 | } | |
2527 | return NULL; | |
2528 | } | |
2529 | ||
2530 | static void setup_modinfo(struct module *mod, struct load_info *info) | |
2531 | { | |
2532 | struct module_attribute *attr; | |
2533 | int i; | |
2534 | ||
2535 | for (i = 0; (attr = modinfo_attrs[i]); i++) { | |
2536 | if (attr->setup) | |
2537 | attr->setup(mod, get_modinfo(info, attr->attr.name)); | |
2538 | } | |
2539 | } | |
2540 | ||
2541 | static void free_modinfo(struct module *mod) | |
2542 | { | |
2543 | struct module_attribute *attr; | |
2544 | int i; | |
2545 | ||
2546 | for (i = 0; (attr = modinfo_attrs[i]); i++) { | |
2547 | if (attr->free) | |
2548 | attr->free(mod); | |
2549 | } | |
2550 | } | |
2551 | ||
2552 | #ifdef CONFIG_KALLSYMS | |
2553 | ||
2554 | /* lookup symbol in given range of kernel_symbols */ | |
2555 | static const struct kernel_symbol *lookup_symbol(const char *name, | |
2556 | const struct kernel_symbol *start, | |
2557 | const struct kernel_symbol *stop) | |
2558 | { | |
2559 | return bsearch(name, start, stop - start, | |
2560 | sizeof(struct kernel_symbol), cmp_name); | |
2561 | } | |
2562 | ||
2563 | static int is_exported(const char *name, unsigned long value, | |
2564 | const struct module *mod) | |
2565 | { | |
2566 | const struct kernel_symbol *ks; | |
2567 | if (!mod) | |
2568 | ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab); | |
2569 | else | |
2570 | ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms); | |
2571 | return ks != NULL && ks->value == value; | |
2572 | } | |
2573 | ||
2574 | /* As per nm */ | |
2575 | static char elf_type(const Elf_Sym *sym, const struct load_info *info) | |
2576 | { | |
2577 | const Elf_Shdr *sechdrs = info->sechdrs; | |
2578 | ||
2579 | if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { | |
2580 | if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) | |
2581 | return 'v'; | |
2582 | else | |
2583 | return 'w'; | |
2584 | } | |
2585 | if (sym->st_shndx == SHN_UNDEF) | |
2586 | return 'U'; | |
2587 | if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu) | |
2588 | return 'a'; | |
2589 | if (sym->st_shndx >= SHN_LORESERVE) | |
2590 | return '?'; | |
2591 | if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR) | |
2592 | return 't'; | |
2593 | if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC | |
2594 | && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) { | |
2595 | if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE)) | |
2596 | return 'r'; | |
2597 | else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) | |
2598 | return 'g'; | |
2599 | else | |
2600 | return 'd'; | |
2601 | } | |
2602 | if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { | |
2603 | if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) | |
2604 | return 's'; | |
2605 | else | |
2606 | return 'b'; | |
2607 | } | |
2608 | if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name, | |
2609 | ".debug")) { | |
2610 | return 'n'; | |
2611 | } | |
2612 | return '?'; | |
2613 | } | |
2614 | ||
2615 | static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, | |
2616 | unsigned int shnum, unsigned int pcpundx) | |
2617 | { | |
2618 | const Elf_Shdr *sec; | |
2619 | ||
2620 | if (src->st_shndx == SHN_UNDEF | |
2621 | || src->st_shndx >= shnum | |
2622 | || !src->st_name) | |
2623 | return false; | |
2624 | ||
2625 | #ifdef CONFIG_KALLSYMS_ALL | |
2626 | if (src->st_shndx == pcpundx) | |
2627 | return true; | |
2628 | #endif | |
2629 | ||
2630 | sec = sechdrs + src->st_shndx; | |
2631 | if (!(sec->sh_flags & SHF_ALLOC) | |
2632 | #ifndef CONFIG_KALLSYMS_ALL | |
2633 | || !(sec->sh_flags & SHF_EXECINSTR) | |
2634 | #endif | |
2635 | || (sec->sh_entsize & INIT_OFFSET_MASK)) | |
2636 | return false; | |
2637 | ||
2638 | return true; | |
2639 | } | |
2640 | ||
2641 | /* | |
2642 | * We only allocate and copy the strings needed by the parts of symtab | |
2643 | * we keep. This is simple, but has the effect of making multiple | |
2644 | * copies of duplicates. We could be more sophisticated, see | |
2645 | * linux-kernel thread starting with | |
2646 | * <73defb5e4bca04a6431392cc341112b1@localhost>. | |
2647 | */ | |
2648 | static void layout_symtab(struct module *mod, struct load_info *info) | |
2649 | { | |
2650 | Elf_Shdr *symsect = info->sechdrs + info->index.sym; | |
2651 | Elf_Shdr *strsect = info->sechdrs + info->index.str; | |
2652 | const Elf_Sym *src; | |
2653 | unsigned int i, nsrc, ndst, strtab_size = 0; | |
2654 | ||
2655 | /* Put symbol section at end of init part of module. */ | |
2656 | symsect->sh_flags |= SHF_ALLOC; | |
2657 | symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect, | |
2658 | info->index.sym) | INIT_OFFSET_MASK; | |
2659 | pr_debug("\t%s\n", info->secstrings + symsect->sh_name); | |
2660 | ||
2661 | src = (void *)info->hdr + symsect->sh_offset; | |
2662 | nsrc = symsect->sh_size / sizeof(*src); | |
2663 | ||
2664 | /* Compute total space required for the core symbols' strtab. */ | |
2665 | for (ndst = i = 0; i < nsrc; i++) { | |
2666 | if (i == 0 || is_livepatch_module(mod) || | |
2667 | is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, | |
2668 | info->index.pcpu)) { | |
2669 | strtab_size += strlen(&info->strtab[src[i].st_name])+1; | |
2670 | ndst++; | |
2671 | } | |
2672 | } | |
2673 | ||
2674 | /* Append room for core symbols at end of core part. */ | |
2675 | info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1); | |
2676 | info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym); | |
2677 | mod->core_layout.size += strtab_size; | |
2678 | mod->core_layout.size = debug_align(mod->core_layout.size); | |
2679 | ||
2680 | /* Put string table section at end of init part of module. */ | |
2681 | strsect->sh_flags |= SHF_ALLOC; | |
2682 | strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect, | |
2683 | info->index.str) | INIT_OFFSET_MASK; | |
2684 | pr_debug("\t%s\n", info->secstrings + strsect->sh_name); | |
2685 | ||
2686 | /* We'll tack temporary mod_kallsyms on the end. */ | |
2687 | mod->init_layout.size = ALIGN(mod->init_layout.size, | |
2688 | __alignof__(struct mod_kallsyms)); | |
2689 | info->mod_kallsyms_init_off = mod->init_layout.size; | |
2690 | mod->init_layout.size += sizeof(struct mod_kallsyms); | |
2691 | mod->init_layout.size = debug_align(mod->init_layout.size); | |
2692 | } | |
2693 | ||
2694 | /* | |
2695 | * We use the full symtab and strtab which layout_symtab arranged to | |
2696 | * be appended to the init section. Later we switch to the cut-down | |
2697 | * core-only ones. | |
2698 | */ | |
2699 | static void add_kallsyms(struct module *mod, const struct load_info *info) | |
2700 | { | |
2701 | unsigned int i, ndst; | |
2702 | const Elf_Sym *src; | |
2703 | Elf_Sym *dst; | |
2704 | char *s; | |
2705 | Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; | |
2706 | ||
2707 | /* Set up to point into init section. */ | |
2708 | mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off; | |
2709 | ||
2710 | mod->kallsyms->symtab = (void *)symsec->sh_addr; | |
2711 | mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym); | |
2712 | /* Make sure we get permanent strtab: don't use info->strtab. */ | |
2713 | mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr; | |
2714 | ||
2715 | /* Set types up while we still have access to sections. */ | |
2716 | for (i = 0; i < mod->kallsyms->num_symtab; i++) | |
2717 | mod->kallsyms->symtab[i].st_info | |
2718 | = elf_type(&mod->kallsyms->symtab[i], info); | |
2719 | ||
2720 | /* Now populate the cut down core kallsyms for after init. */ | |
2721 | mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs; | |
2722 | mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs; | |
2723 | src = mod->kallsyms->symtab; | |
2724 | for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) { | |
2725 | if (i == 0 || is_livepatch_module(mod) || | |
2726 | is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, | |
2727 | info->index.pcpu)) { | |
2728 | dst[ndst] = src[i]; | |
2729 | dst[ndst++].st_name = s - mod->core_kallsyms.strtab; | |
2730 | s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name], | |
2731 | KSYM_NAME_LEN) + 1; | |
2732 | } | |
2733 | } | |
2734 | mod->core_kallsyms.num_symtab = ndst; | |
2735 | } | |
2736 | #else | |
2737 | static inline void layout_symtab(struct module *mod, struct load_info *info) | |
2738 | { | |
2739 | } | |
2740 | ||
2741 | static void add_kallsyms(struct module *mod, const struct load_info *info) | |
2742 | { | |
2743 | } | |
2744 | #endif /* CONFIG_KALLSYMS */ | |
2745 | ||
2746 | static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num) | |
2747 | { | |
2748 | if (!debug) | |
2749 | return; | |
2750 | #ifdef CONFIG_DYNAMIC_DEBUG | |
2751 | if (ddebug_add_module(debug, num, mod->name)) | |
2752 | pr_err("dynamic debug error adding module: %s\n", | |
2753 | debug->modname); | |
2754 | #endif | |
2755 | } | |
2756 | ||
2757 | static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug) | |
2758 | { | |
2759 | if (debug) | |
2760 | ddebug_remove_module(mod->name); | |
2761 | } | |
2762 | ||
2763 | void * __weak module_alloc(unsigned long size) | |
2764 | { | |
2765 | return vmalloc_exec(size); | |
2766 | } | |
2767 | ||
2768 | #ifdef CONFIG_DEBUG_KMEMLEAK | |
2769 | static void kmemleak_load_module(const struct module *mod, | |
2770 | const struct load_info *info) | |
2771 | { | |
2772 | unsigned int i; | |
2773 | ||
2774 | /* only scan the sections containing data */ | |
2775 | kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL); | |
2776 | ||
2777 | for (i = 1; i < info->hdr->e_shnum; i++) { | |
2778 | /* Scan all writable sections that's not executable */ | |
2779 | if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) || | |
2780 | !(info->sechdrs[i].sh_flags & SHF_WRITE) || | |
2781 | (info->sechdrs[i].sh_flags & SHF_EXECINSTR)) | |
2782 | continue; | |
2783 | ||
2784 | kmemleak_scan_area((void *)info->sechdrs[i].sh_addr, | |
2785 | info->sechdrs[i].sh_size, GFP_KERNEL); | |
2786 | } | |
2787 | } | |
2788 | #else | |
2789 | static inline void kmemleak_load_module(const struct module *mod, | |
2790 | const struct load_info *info) | |
2791 | { | |
2792 | } | |
2793 | #endif | |
2794 | ||
2795 | #ifdef CONFIG_MODULE_SIG | |
2796 | static int module_sig_check(struct load_info *info, int flags) | |
2797 | { | |
2798 | int err = -ENOKEY; | |
2799 | const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; | |
2800 | const void *mod = info->hdr; | |
2801 | ||
2802 | /* | |
2803 | * Require flags == 0, as a module with version information | |
2804 | * removed is no longer the module that was signed | |
2805 | */ | |
2806 | if (flags == 0 && | |
2807 | info->len > markerlen && | |
2808 | memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { | |
2809 | /* We truncate the module to discard the signature */ | |
2810 | info->len -= markerlen; | |
2811 | err = mod_verify_sig(mod, &info->len); | |
2812 | } | |
2813 | ||
2814 | if (!err) { | |
2815 | info->sig_ok = true; | |
2816 | return 0; | |
2817 | } | |
2818 | ||
2819 | /* Not having a signature is only an error if we're strict. */ | |
2820 | if (err == -ENOKEY && !sig_enforce && | |
2821 | !kernel_is_locked_down("Loading of unsigned modules")) | |
2822 | err = 0; | |
2823 | ||
2824 | return err; | |
2825 | } | |
2826 | #else /* !CONFIG_MODULE_SIG */ | |
2827 | static int module_sig_check(struct load_info *info, int flags) | |
2828 | { | |
2829 | return 0; | |
2830 | } | |
2831 | #endif /* !CONFIG_MODULE_SIG */ | |
2832 | ||
2833 | /* Sanity checks against invalid binaries, wrong arch, weird elf version. */ | |
2834 | static int elf_header_check(struct load_info *info) | |
2835 | { | |
2836 | if (info->len < sizeof(*(info->hdr))) | |
2837 | return -ENOEXEC; | |
2838 | ||
2839 | if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0 | |
2840 | || info->hdr->e_type != ET_REL | |
2841 | || !elf_check_arch(info->hdr) | |
2842 | || info->hdr->e_shentsize != sizeof(Elf_Shdr)) | |
2843 | return -ENOEXEC; | |
2844 | ||
2845 | if (info->hdr->e_shoff >= info->len | |
2846 | || (info->hdr->e_shnum * sizeof(Elf_Shdr) > | |
2847 | info->len - info->hdr->e_shoff)) | |
2848 | return -ENOEXEC; | |
2849 | ||
2850 | return 0; | |
2851 | } | |
2852 | ||
2853 | #define COPY_CHUNK_SIZE (16*PAGE_SIZE) | |
2854 | ||
2855 | static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len) | |
2856 | { | |
2857 | do { | |
2858 | unsigned long n = min(len, COPY_CHUNK_SIZE); | |
2859 | ||
2860 | if (copy_from_user(dst, usrc, n) != 0) | |
2861 | return -EFAULT; | |
2862 | cond_resched(); | |
2863 | dst += n; | |
2864 | usrc += n; | |
2865 | len -= n; | |
2866 | } while (len); | |
2867 | return 0; | |
2868 | } | |
2869 | ||
2870 | #ifdef CONFIG_LIVEPATCH | |
2871 | static int check_modinfo_livepatch(struct module *mod, struct load_info *info) | |
2872 | { | |
2873 | if (get_modinfo(info, "livepatch")) { | |
2874 | mod->klp = true; | |
2875 | add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK); | |
2876 | pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n", | |
2877 | mod->name); | |
2878 | } | |
2879 | ||
2880 | return 0; | |
2881 | } | |
2882 | #else /* !CONFIG_LIVEPATCH */ | |
2883 | static int check_modinfo_livepatch(struct module *mod, struct load_info *info) | |
2884 | { | |
2885 | if (get_modinfo(info, "livepatch")) { | |
2886 | pr_err("%s: module is marked as livepatch module, but livepatch support is disabled", | |
2887 | mod->name); | |
2888 | return -ENOEXEC; | |
2889 | } | |
2890 | ||
2891 | return 0; | |
2892 | } | |
2893 | #endif /* CONFIG_LIVEPATCH */ | |
2894 | ||
2895 | static void check_modinfo_retpoline(struct module *mod, struct load_info *info) | |
2896 | { | |
2897 | if (retpoline_module_ok(get_modinfo(info, "retpoline"))) | |
2898 | return; | |
2899 | ||
2900 | pr_warn("%s: loading module not compiled with retpoline compiler.\n", | |
2901 | mod->name); | |
2902 | } | |
2903 | ||
2904 | /* Sets info->hdr and info->len. */ | |
2905 | static int copy_module_from_user(const void __user *umod, unsigned long len, | |
2906 | struct load_info *info) | |
2907 | { | |
2908 | int err; | |
2909 | ||
2910 | info->len = len; | |
2911 | if (info->len < sizeof(*(info->hdr))) | |
2912 | return -ENOEXEC; | |
2913 | ||
2914 | err = security_kernel_read_file(NULL, READING_MODULE); | |
2915 | if (err) | |
2916 | return err; | |
2917 | ||
2918 | /* Suck in entire file: we'll want most of it. */ | |
2919 | info->hdr = __vmalloc(info->len, | |
2920 | GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL); | |
2921 | if (!info->hdr) | |
2922 | return -ENOMEM; | |
2923 | ||
2924 | if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) { | |
2925 | vfree(info->hdr); | |
2926 | return -EFAULT; | |
2927 | } | |
2928 | ||
2929 | return 0; | |
2930 | } | |
2931 | ||
2932 | static void free_copy(struct load_info *info) | |
2933 | { | |
2934 | vfree(info->hdr); | |
2935 | } | |
2936 | ||
2937 | static int rewrite_section_headers(struct load_info *info, int flags) | |
2938 | { | |
2939 | unsigned int i; | |
2940 | ||
2941 | /* This should always be true, but let's be sure. */ | |
2942 | info->sechdrs[0].sh_addr = 0; | |
2943 | ||
2944 | for (i = 1; i < info->hdr->e_shnum; i++) { | |
2945 | Elf_Shdr *shdr = &info->sechdrs[i]; | |
2946 | if (shdr->sh_type != SHT_NOBITS | |
2947 | && info->len < shdr->sh_offset + shdr->sh_size) { | |
2948 | pr_err("Module len %lu truncated\n", info->len); | |
2949 | return -ENOEXEC; | |
2950 | } | |
2951 | ||
2952 | /* Mark all sections sh_addr with their address in the | |
2953 | temporary image. */ | |
2954 | shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; | |
2955 | ||
2956 | #ifndef CONFIG_MODULE_UNLOAD | |
2957 | /* Don't load .exit sections */ | |
2958 | if (strstarts(info->secstrings+shdr->sh_name, ".exit")) | |
2959 | shdr->sh_flags &= ~(unsigned long)SHF_ALLOC; | |
2960 | #endif | |
2961 | } | |
2962 | ||
2963 | /* Track but don't keep modinfo and version sections. */ | |
2964 | if (flags & MODULE_INIT_IGNORE_MODVERSIONS) | |
2965 | info->index.vers = 0; /* Pretend no __versions section! */ | |
2966 | else | |
2967 | info->index.vers = find_sec(info, "__versions"); | |
2968 | info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; | |
2969 | ||
2970 | info->index.info = find_sec(info, ".modinfo"); | |
2971 | if (!info->index.info) | |
2972 | info->name = "(missing .modinfo section)"; | |
2973 | else | |
2974 | info->name = get_modinfo(info, "name"); | |
2975 | info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; | |
2976 | ||
2977 | return 0; | |
2978 | } | |
2979 | ||
2980 | /* | |
2981 | * Set up our basic convenience variables (pointers to section headers, | |
2982 | * search for module section index etc), and do some basic section | |
2983 | * verification. | |
2984 | * | |
2985 | * Return the temporary module pointer (we'll replace it with the final | |
2986 | * one when we move the module sections around). | |
2987 | */ | |
2988 | static struct module *setup_load_info(struct load_info *info, int flags) | |
2989 | { | |
2990 | unsigned int i; | |
2991 | int err; | |
2992 | struct module *mod; | |
2993 | ||
2994 | /* Set up the convenience variables */ | |
2995 | info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; | |
2996 | info->secstrings = (void *)info->hdr | |
2997 | + info->sechdrs[info->hdr->e_shstrndx].sh_offset; | |
2998 | ||
2999 | err = rewrite_section_headers(info, flags); | |
3000 | if (err) | |
3001 | return ERR_PTR(err); | |
3002 | ||
3003 | /* Find internal symbols and strings. */ | |
3004 | for (i = 1; i < info->hdr->e_shnum; i++) { | |
3005 | if (info->sechdrs[i].sh_type == SHT_SYMTAB) { | |
3006 | info->index.sym = i; | |
3007 | info->index.str = info->sechdrs[i].sh_link; | |
3008 | info->strtab = (char *)info->hdr | |
3009 | + info->sechdrs[info->index.str].sh_offset; | |
3010 | break; | |
3011 | } | |
3012 | } | |
3013 | ||
3014 | info->index.mod = find_sec(info, ".gnu.linkonce.this_module"); | |
3015 | if (!info->index.mod) { | |
3016 | pr_warn("%s: No module found in object\n", | |
3017 | info->name ?: "(missing .modinfo name field)"); | |
3018 | return ERR_PTR(-ENOEXEC); | |
3019 | } | |
3020 | /* This is temporary: point mod into copy of data. */ | |
3021 | mod = (void *)info->sechdrs[info->index.mod].sh_addr; | |
3022 | ||
3023 | /* | |
3024 | * If we didn't load the .modinfo 'name' field, fall back to | |
3025 | * on-disk struct mod 'name' field. | |
3026 | */ | |
3027 | if (!info->name) | |
3028 | info->name = mod->name; | |
3029 | ||
3030 | if (info->index.sym == 0) { | |
3031 | pr_warn("%s: module has no symbols (stripped?)\n", info->name); | |
3032 | return ERR_PTR(-ENOEXEC); | |
3033 | } | |
3034 | ||
3035 | info->index.pcpu = find_pcpusec(info); | |
3036 | ||
3037 | /* Check module struct version now, before we try to use module. */ | |
3038 | if (!check_modstruct_version(info, mod)) | |
3039 | return ERR_PTR(-ENOEXEC); | |
3040 | ||
3041 | return mod; | |
3042 | } | |
3043 | ||
3044 | static int check_modinfo(struct module *mod, struct load_info *info, int flags) | |
3045 | { | |
3046 | const char *modmagic = get_modinfo(info, "vermagic"); | |
3047 | int err; | |
3048 | ||
3049 | if (flags & MODULE_INIT_IGNORE_VERMAGIC) | |
3050 | modmagic = NULL; | |
3051 | ||
3052 | /* This is allowed: modprobe --force will invalidate it. */ | |
3053 | if (!modmagic) { | |
3054 | err = try_to_force_load(mod, "bad vermagic"); | |
3055 | if (err) | |
3056 | return err; | |
3057 | } else if (!same_magic(modmagic, vermagic, info->index.vers)) { | |
3058 | pr_err("%s: version magic '%s' should be '%s'\n", | |
3059 | info->name, modmagic, vermagic); | |
3060 | return -ENOEXEC; | |
3061 | } | |
3062 | ||
3063 | if (!get_modinfo(info, "intree")) { | |
3064 | if (!test_taint(TAINT_OOT_MODULE)) | |
3065 | pr_warn("%s: loading out-of-tree module taints kernel.\n", | |
3066 | mod->name); | |
3067 | add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); | |
3068 | } | |
3069 | ||
3070 | check_modinfo_retpoline(mod, info); | |
3071 | ||
3072 | if (get_modinfo(info, "staging")) { | |
3073 | add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); | |
3074 | pr_warn("%s: module is from the staging directory, the quality " | |
3075 | "is unknown, you have been warned.\n", mod->name); | |
3076 | } | |
3077 | ||
3078 | err = check_modinfo_livepatch(mod, info); | |
3079 | if (err) | |
3080 | return err; | |
3081 | ||
3082 | /* Set up license info based on the info section */ | |
3083 | set_license(mod, get_modinfo(info, "license")); | |
3084 | ||
3085 | return 0; | |
3086 | } | |
3087 | ||
3088 | static int find_module_sections(struct module *mod, struct load_info *info) | |
3089 | { | |
3090 | mod->kp = section_objs(info, "__param", | |
3091 | sizeof(*mod->kp), &mod->num_kp); | |
3092 | mod->syms = section_objs(info, "__ksymtab", | |
3093 | sizeof(*mod->syms), &mod->num_syms); | |
3094 | mod->crcs = section_addr(info, "__kcrctab"); | |
3095 | mod->gpl_syms = section_objs(info, "__ksymtab_gpl", | |
3096 | sizeof(*mod->gpl_syms), | |
3097 | &mod->num_gpl_syms); | |
3098 | mod->gpl_crcs = section_addr(info, "__kcrctab_gpl"); | |
3099 | mod->gpl_future_syms = section_objs(info, | |
3100 | "__ksymtab_gpl_future", | |
3101 | sizeof(*mod->gpl_future_syms), | |
3102 | &mod->num_gpl_future_syms); | |
3103 | mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future"); | |
3104 | ||
3105 | #ifdef CONFIG_UNUSED_SYMBOLS | |
3106 | mod->unused_syms = section_objs(info, "__ksymtab_unused", | |
3107 | sizeof(*mod->unused_syms), | |
3108 | &mod->num_unused_syms); | |
3109 | mod->unused_crcs = section_addr(info, "__kcrctab_unused"); | |
3110 | mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl", | |
3111 | sizeof(*mod->unused_gpl_syms), | |
3112 | &mod->num_unused_gpl_syms); | |
3113 | mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl"); | |
3114 | #endif | |
3115 | #ifdef CONFIG_CONSTRUCTORS | |
3116 | mod->ctors = section_objs(info, ".ctors", | |
3117 | sizeof(*mod->ctors), &mod->num_ctors); | |
3118 | if (!mod->ctors) | |
3119 | mod->ctors = section_objs(info, ".init_array", | |
3120 | sizeof(*mod->ctors), &mod->num_ctors); | |
3121 | else if (find_sec(info, ".init_array")) { | |
3122 | /* | |
3123 | * This shouldn't happen with same compiler and binutils | |
3124 | * building all parts of the module. | |
3125 | */ | |
3126 | pr_warn("%s: has both .ctors and .init_array.\n", | |
3127 | mod->name); | |
3128 | return -EINVAL; | |
3129 | } | |
3130 | #endif | |
3131 | ||
3132 | #ifdef CONFIG_TRACEPOINTS | |
3133 | mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", | |
3134 | sizeof(*mod->tracepoints_ptrs), | |
3135 | &mod->num_tracepoints); | |
3136 | #endif | |
3137 | #ifdef HAVE_JUMP_LABEL | |
3138 | mod->jump_entries = section_objs(info, "__jump_table", | |
3139 | sizeof(*mod->jump_entries), | |
3140 | &mod->num_jump_entries); | |
3141 | #endif | |
3142 | #ifdef CONFIG_EVENT_TRACING | |
3143 | mod->trace_events = section_objs(info, "_ftrace_events", | |
3144 | sizeof(*mod->trace_events), | |
3145 | &mod->num_trace_events); | |
3146 | mod->trace_evals = section_objs(info, "_ftrace_eval_map", | |
3147 | sizeof(*mod->trace_evals), | |
3148 | &mod->num_trace_evals); | |
3149 | #endif | |
3150 | #ifdef CONFIG_TRACING | |
3151 | mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt", | |
3152 | sizeof(*mod->trace_bprintk_fmt_start), | |
3153 | &mod->num_trace_bprintk_fmt); | |
3154 | #endif | |
3155 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD | |
3156 | /* sechdrs[0].sh_size is always zero */ | |
3157 | mod->ftrace_callsites = section_objs(info, "__mcount_loc", | |
3158 | sizeof(*mod->ftrace_callsites), | |
3159 | &mod->num_ftrace_callsites); | |
3160 | #endif | |
3161 | ||
3162 | mod->extable = section_objs(info, "__ex_table", | |
3163 | sizeof(*mod->extable), &mod->num_exentries); | |
3164 | ||
3165 | if (section_addr(info, "__obsparm")) | |
3166 | pr_warn("%s: Ignoring obsolete parameters\n", mod->name); | |
3167 | ||
3168 | info->debug = section_objs(info, "__verbose", | |
3169 | sizeof(*info->debug), &info->num_debug); | |
3170 | ||
3171 | return 0; | |
3172 | } | |
3173 | ||
3174 | static int move_module(struct module *mod, struct load_info *info) | |
3175 | { | |
3176 | int i; | |
3177 | void *ptr; | |
3178 | ||
3179 | /* Do the allocs. */ | |
3180 | ptr = module_alloc(mod->core_layout.size); | |
3181 | /* | |
3182 | * The pointer to this block is stored in the module structure | |
3183 | * which is inside the block. Just mark it as not being a | |
3184 | * leak. | |
3185 | */ | |
3186 | kmemleak_not_leak(ptr); | |
3187 | if (!ptr) | |
3188 | return -ENOMEM; | |
3189 | ||
3190 | memset(ptr, 0, mod->core_layout.size); | |
3191 | mod->core_layout.base = ptr; | |
3192 | ||
3193 | if (mod->init_layout.size) { | |
3194 | ptr = module_alloc(mod->init_layout.size); | |
3195 | /* | |
3196 | * The pointer to this block is stored in the module structure | |
3197 | * which is inside the block. This block doesn't need to be | |
3198 | * scanned as it contains data and code that will be freed | |
3199 | * after the module is initialized. | |
3200 | */ | |
3201 | kmemleak_ignore(ptr); | |
3202 | if (!ptr) { | |
3203 | module_memfree(mod->core_layout.base); | |
3204 | return -ENOMEM; | |
3205 | } | |
3206 | memset(ptr, 0, mod->init_layout.size); | |
3207 | mod->init_layout.base = ptr; | |
3208 | } else | |
3209 | mod->init_layout.base = NULL; | |
3210 | ||
3211 | /* Transfer each section which specifies SHF_ALLOC */ | |
3212 | pr_debug("final section addresses:\n"); | |
3213 | for (i = 0; i < info->hdr->e_shnum; i++) { | |
3214 | void *dest; | |
3215 | Elf_Shdr *shdr = &info->sechdrs[i]; | |
3216 | ||
3217 | if (!(shdr->sh_flags & SHF_ALLOC)) | |
3218 | continue; | |
3219 | ||
3220 | if (shdr->sh_entsize & INIT_OFFSET_MASK) | |
3221 | dest = mod->init_layout.base | |
3222 | + (shdr->sh_entsize & ~INIT_OFFSET_MASK); | |
3223 | else | |
3224 | dest = mod->core_layout.base + shdr->sh_entsize; | |
3225 | ||
3226 | if (shdr->sh_type != SHT_NOBITS) | |
3227 | memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size); | |
3228 | /* Update sh_addr to point to copy in image. */ | |
3229 | shdr->sh_addr = (unsigned long)dest; | |
3230 | pr_debug("\t0x%lx %s\n", | |
3231 | (long)shdr->sh_addr, info->secstrings + shdr->sh_name); | |
3232 | } | |
3233 | ||
3234 | return 0; | |
3235 | } | |
3236 | ||
3237 | static int check_module_license_and_versions(struct module *mod) | |
3238 | { | |
3239 | int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE); | |
3240 | ||
3241 | /* | |
3242 | * ndiswrapper is under GPL by itself, but loads proprietary modules. | |
3243 | * Don't use add_taint_module(), as it would prevent ndiswrapper from | |
3244 | * using GPL-only symbols it needs. | |
3245 | */ | |
3246 | if (strcmp(mod->name, "ndiswrapper") == 0) | |
3247 | add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE); | |
3248 | ||
3249 | /* driverloader was caught wrongly pretending to be under GPL */ | |
3250 | if (strcmp(mod->name, "driverloader") == 0) | |
3251 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE, | |
3252 | LOCKDEP_NOW_UNRELIABLE); | |
3253 | ||
3254 | /* lve claims to be GPL but upstream won't provide source */ | |
3255 | if (strcmp(mod->name, "lve") == 0) | |
3256 | add_taint_module(mod, TAINT_PROPRIETARY_MODULE, | |
3257 | LOCKDEP_NOW_UNRELIABLE); | |
3258 | ||
3259 | if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE)) | |
3260 | pr_warn("%s: module license taints kernel.\n", mod->name); | |
3261 | ||
3262 | #ifdef CONFIG_MODVERSIONS | |
3263 | if ((mod->num_syms && !mod->crcs) | |
3264 | || (mod->num_gpl_syms && !mod->gpl_crcs) | |
3265 | || (mod->num_gpl_future_syms && !mod->gpl_future_crcs) | |
3266 | #ifdef CONFIG_UNUSED_SYMBOLS | |
3267 | || (mod->num_unused_syms && !mod->unused_crcs) | |
3268 | || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs) | |
3269 | #endif | |
3270 | ) { | |
3271 | return try_to_force_load(mod, | |
3272 | "no versions for exported symbols"); | |
3273 | } | |
3274 | #endif | |
3275 | return 0; | |
3276 | } | |
3277 | ||
3278 | static void flush_module_icache(const struct module *mod) | |
3279 | { | |
3280 | mm_segment_t old_fs; | |
3281 | ||
3282 | /* flush the icache in correct context */ | |
3283 | old_fs = get_fs(); | |
3284 | set_fs(KERNEL_DS); | |
3285 | ||
3286 | /* | |
3287 | * Flush the instruction cache, since we've played with text. | |
3288 | * Do it before processing of module parameters, so the module | |
3289 | * can provide parameter accessor functions of its own. | |
3290 | */ | |
3291 | if (mod->init_layout.base) | |
3292 | flush_icache_range((unsigned long)mod->init_layout.base, | |
3293 | (unsigned long)mod->init_layout.base | |
3294 | + mod->init_layout.size); | |
3295 | flush_icache_range((unsigned long)mod->core_layout.base, | |
3296 | (unsigned long)mod->core_layout.base + mod->core_layout.size); | |
3297 | ||
3298 | set_fs(old_fs); | |
3299 | } | |
3300 | ||
3301 | int __weak module_frob_arch_sections(Elf_Ehdr *hdr, | |
3302 | Elf_Shdr *sechdrs, | |
3303 | char *secstrings, | |
3304 | struct module *mod) | |
3305 | { | |
3306 | return 0; | |
3307 | } | |
3308 | ||
3309 | /* module_blacklist is a comma-separated list of module names */ | |
3310 | static char *module_blacklist; | |
3311 | static bool blacklisted(const char *module_name) | |
3312 | { | |
3313 | const char *p; | |
3314 | size_t len; | |
3315 | ||
3316 | if (!module_blacklist) | |
3317 | return false; | |
3318 | ||
3319 | for (p = module_blacklist; *p; p += len) { | |
3320 | len = strcspn(p, ","); | |
3321 | if (strlen(module_name) == len && !memcmp(module_name, p, len)) | |
3322 | return true; | |
3323 | if (p[len] == ',') | |
3324 | len++; | |
3325 | } | |
3326 | return false; | |
3327 | } | |
3328 | core_param(module_blacklist, module_blacklist, charp, 0400); | |
3329 | ||
3330 | static struct module *layout_and_allocate(struct load_info *info, int flags) | |
3331 | { | |
3332 | /* Module within temporary copy. */ | |
3333 | struct module *mod; | |
3334 | unsigned int ndx; | |
3335 | int err; | |
3336 | ||
3337 | mod = setup_load_info(info, flags); | |
3338 | if (IS_ERR(mod)) | |
3339 | return mod; | |
3340 | ||
3341 | if (blacklisted(info->name)) | |
3342 | return ERR_PTR(-EPERM); | |
3343 | ||
3344 | err = check_modinfo(mod, info, flags); | |
3345 | if (err) | |
3346 | return ERR_PTR(err); | |
3347 | ||
3348 | /* Allow arches to frob section contents and sizes. */ | |
3349 | err = module_frob_arch_sections(info->hdr, info->sechdrs, | |
3350 | info->secstrings, mod); | |
3351 | if (err < 0) | |
3352 | return ERR_PTR(err); | |
3353 | ||
3354 | /* We will do a special allocation for per-cpu sections later. */ | |
3355 | info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; | |
3356 | ||
3357 | /* | |
3358 | * Mark ro_after_init section with SHF_RO_AFTER_INIT so that | |
3359 | * layout_sections() can put it in the right place. | |
3360 | * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set. | |
3361 | */ | |
3362 | ndx = find_sec(info, ".data..ro_after_init"); | |
3363 | if (ndx) | |
3364 | info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; | |
3365 | ||
3366 | /* Determine total sizes, and put offsets in sh_entsize. For now | |
3367 | this is done generically; there doesn't appear to be any | |
3368 | special cases for the architectures. */ | |
3369 | layout_sections(mod, info); | |
3370 | layout_symtab(mod, info); | |
3371 | ||
3372 | /* Allocate and move to the final place */ | |
3373 | err = move_module(mod, info); | |
3374 | if (err) | |
3375 | return ERR_PTR(err); | |
3376 | ||
3377 | /* Module has been copied to its final place now: return it. */ | |
3378 | mod = (void *)info->sechdrs[info->index.mod].sh_addr; | |
3379 | kmemleak_load_module(mod, info); | |
3380 | return mod; | |
3381 | } | |
3382 | ||
3383 | /* mod is no longer valid after this! */ | |
3384 | static void module_deallocate(struct module *mod, struct load_info *info) | |
3385 | { | |
3386 | percpu_modfree(mod); | |
3387 | module_arch_freeing_init(mod); | |
3388 | module_memfree(mod->init_layout.base); | |
3389 | module_memfree(mod->core_layout.base); | |
3390 | } | |
3391 | ||
3392 | int __weak module_finalize(const Elf_Ehdr *hdr, | |
3393 | const Elf_Shdr *sechdrs, | |
3394 | struct module *me) | |
3395 | { | |
3396 | return 0; | |
3397 | } | |
3398 | ||
3399 | static int post_relocation(struct module *mod, const struct load_info *info) | |
3400 | { | |
3401 | /* Sort exception table now relocations are done. */ | |
3402 | sort_extable(mod->extable, mod->extable + mod->num_exentries); | |
3403 | ||
3404 | /* Copy relocated percpu area over. */ | |
3405 | percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr, | |
3406 | info->sechdrs[info->index.pcpu].sh_size); | |
3407 | ||
3408 | /* Setup kallsyms-specific fields. */ | |
3409 | add_kallsyms(mod, info); | |
3410 | ||
3411 | /* Arch-specific module finalizing. */ | |
3412 | return module_finalize(info->hdr, info->sechdrs, mod); | |
3413 | } | |
3414 | ||
3415 | /* Is this module of this name done loading? No locks held. */ | |
3416 | static bool finished_loading(const char *name) | |
3417 | { | |
3418 | struct module *mod; | |
3419 | bool ret; | |
3420 | ||
3421 | /* | |
3422 | * The module_mutex should not be a heavily contended lock; | |
3423 | * if we get the occasional sleep here, we'll go an extra iteration | |
3424 | * in the wait_event_interruptible(), which is harmless. | |
3425 | */ | |
3426 | sched_annotate_sleep(); | |
3427 | mutex_lock(&module_mutex); | |
3428 | mod = find_module_all(name, strlen(name), true); | |
3429 | ret = !mod || mod->state == MODULE_STATE_LIVE; | |
3430 | mutex_unlock(&module_mutex); | |
3431 | ||
3432 | return ret; | |
3433 | } | |
3434 | ||
3435 | /* Call module constructors. */ | |
3436 | static void do_mod_ctors(struct module *mod) | |
3437 | { | |
3438 | #ifdef CONFIG_CONSTRUCTORS | |
3439 | unsigned long i; | |
3440 | ||
3441 | for (i = 0; i < mod->num_ctors; i++) | |
3442 | mod->ctors[i](); | |
3443 | #endif | |
3444 | } | |
3445 | ||
3446 | /* For freeing module_init on success, in case kallsyms traversing */ | |
3447 | struct mod_initfree { | |
3448 | struct rcu_head rcu; | |
3449 | void *module_init; | |
3450 | }; | |
3451 | ||
3452 | static void do_free_init(struct rcu_head *head) | |
3453 | { | |
3454 | struct mod_initfree *m = container_of(head, struct mod_initfree, rcu); | |
3455 | module_memfree(m->module_init); | |
3456 | kfree(m); | |
3457 | } | |
3458 | ||
3459 | /* | |
3460 | * This is where the real work happens. | |
3461 | * | |
3462 | * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb | |
3463 | * helper command 'lx-symbols'. | |
3464 | */ | |
3465 | static noinline int do_init_module(struct module *mod) | |
3466 | { | |
3467 | int ret = 0; | |
3468 | struct mod_initfree *freeinit; | |
3469 | ||
3470 | freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL); | |
3471 | if (!freeinit) { | |
3472 | ret = -ENOMEM; | |
3473 | goto fail; | |
3474 | } | |
3475 | freeinit->module_init = mod->init_layout.base; | |
3476 | ||
3477 | /* | |
3478 | * We want to find out whether @mod uses async during init. Clear | |
3479 | * PF_USED_ASYNC. async_schedule*() will set it. | |
3480 | */ | |
3481 | current->flags &= ~PF_USED_ASYNC; | |
3482 | ||
3483 | do_mod_ctors(mod); | |
3484 | /* Start the module */ | |
3485 | if (mod->init != NULL) | |
3486 | ret = do_one_initcall(mod->init); | |
3487 | if (ret < 0) { | |
3488 | goto fail_free_freeinit; | |
3489 | } | |
3490 | if (ret > 0) { | |
3491 | pr_warn("%s: '%s'->init suspiciously returned %d, it should " | |
3492 | "follow 0/-E convention\n" | |
3493 | "%s: loading module anyway...\n", | |
3494 | __func__, mod->name, ret, __func__); | |
3495 | dump_stack(); | |
3496 | } | |
3497 | ||
3498 | /* Now it's a first class citizen! */ | |
3499 | mod->state = MODULE_STATE_LIVE; | |
3500 | blocking_notifier_call_chain(&module_notify_list, | |
3501 | MODULE_STATE_LIVE, mod); | |
3502 | ||
3503 | /* | |
3504 | * We need to finish all async code before the module init sequence | |
3505 | * is done. This has potential to deadlock. For example, a newly | |
3506 | * detected block device can trigger request_module() of the | |
3507 | * default iosched from async probing task. Once userland helper | |
3508 | * reaches here, async_synchronize_full() will wait on the async | |
3509 | * task waiting on request_module() and deadlock. | |
3510 | * | |
3511 | * This deadlock is avoided by perfomring async_synchronize_full() | |
3512 | * iff module init queued any async jobs. This isn't a full | |
3513 | * solution as it will deadlock the same if module loading from | |
3514 | * async jobs nests more than once; however, due to the various | |
3515 | * constraints, this hack seems to be the best option for now. | |
3516 | * Please refer to the following thread for details. | |
3517 | * | |
3518 | * http://thread.gmane.org/gmane.linux.kernel/1420814 | |
3519 | */ | |
3520 | if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC)) | |
3521 | async_synchronize_full(); | |
3522 | ||
3523 | ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base + | |
3524 | mod->init_layout.size); | |
3525 | mutex_lock(&module_mutex); | |
3526 | /* Drop initial reference. */ | |
3527 | module_put(mod); | |
3528 | trim_init_extable(mod); | |
3529 | #ifdef CONFIG_KALLSYMS | |
3530 | /* Switch to core kallsyms now init is done: kallsyms may be walking! */ | |
3531 | rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms); | |
3532 | #endif | |
3533 | module_enable_ro(mod, true); | |
3534 | mod_tree_remove_init(mod); | |
3535 | disable_ro_nx(&mod->init_layout); | |
3536 | module_arch_freeing_init(mod); | |
3537 | mod->init_layout.base = NULL; | |
3538 | mod->init_layout.size = 0; | |
3539 | mod->init_layout.ro_size = 0; | |
3540 | mod->init_layout.ro_after_init_size = 0; | |
3541 | mod->init_layout.text_size = 0; | |
3542 | /* | |
3543 | * We want to free module_init, but be aware that kallsyms may be | |
3544 | * walking this with preempt disabled. In all the failure paths, we | |
3545 | * call synchronize_sched(), but we don't want to slow down the success | |
3546 | * path, so use actual RCU here. | |
3547 | * Note that module_alloc() on most architectures creates W+X page | |
3548 | * mappings which won't be cleaned up until do_free_init() runs. Any | |
3549 | * code such as mark_rodata_ro() which depends on those mappings to | |
3550 | * be cleaned up needs to sync with the queued work - ie | |
3551 | * rcu_barrier_sched() | |
3552 | */ | |
3553 | call_rcu_sched(&freeinit->rcu, do_free_init); | |
3554 | mutex_unlock(&module_mutex); | |
3555 | wake_up_all(&module_wq); | |
3556 | ||
3557 | return 0; | |
3558 | ||
3559 | fail_free_freeinit: | |
3560 | kfree(freeinit); | |
3561 | fail: | |
3562 | /* Try to protect us from buggy refcounters. */ | |
3563 | mod->state = MODULE_STATE_GOING; | |
3564 | synchronize_sched(); | |
3565 | module_put(mod); | |
3566 | blocking_notifier_call_chain(&module_notify_list, | |
3567 | MODULE_STATE_GOING, mod); | |
3568 | klp_module_going(mod); | |
3569 | ftrace_release_mod(mod); | |
3570 | free_module(mod); | |
3571 | wake_up_all(&module_wq); | |
3572 | return ret; | |
3573 | } | |
3574 | ||
3575 | static int may_init_module(void) | |
3576 | { | |
3577 | if (!capable(CAP_SYS_MODULE) || modules_disabled) | |
3578 | return -EPERM; | |
3579 | ||
3580 | return 0; | |
3581 | } | |
3582 | ||
3583 | /* | |
3584 | * We try to place it in the list now to make sure it's unique before | |
3585 | * we dedicate too many resources. In particular, temporary percpu | |
3586 | * memory exhaustion. | |
3587 | */ | |
3588 | static int add_unformed_module(struct module *mod) | |
3589 | { | |
3590 | int err; | |
3591 | struct module *old; | |
3592 | ||
3593 | mod->state = MODULE_STATE_UNFORMED; | |
3594 | ||
3595 | again: | |
3596 | mutex_lock(&module_mutex); | |
3597 | old = find_module_all(mod->name, strlen(mod->name), true); | |
3598 | if (old != NULL) { | |
3599 | if (old->state != MODULE_STATE_LIVE) { | |
3600 | /* Wait in case it fails to load. */ | |
3601 | mutex_unlock(&module_mutex); | |
3602 | err = wait_event_interruptible(module_wq, | |
3603 | finished_loading(mod->name)); | |
3604 | if (err) | |
3605 | goto out_unlocked; | |
3606 | goto again; | |
3607 | } | |
3608 | err = -EEXIST; | |
3609 | goto out; | |
3610 | } | |
3611 | mod_update_bounds(mod); | |
3612 | list_add_rcu(&mod->list, &modules); | |
3613 | mod_tree_insert(mod); | |
3614 | err = 0; | |
3615 | ||
3616 | out: | |
3617 | mutex_unlock(&module_mutex); | |
3618 | out_unlocked: | |
3619 | return err; | |
3620 | } | |
3621 | ||
3622 | static int complete_formation(struct module *mod, struct load_info *info) | |
3623 | { | |
3624 | int err; | |
3625 | ||
3626 | mutex_lock(&module_mutex); | |
3627 | ||
3628 | /* Find duplicate symbols (must be called under lock). */ | |
3629 | err = verify_export_symbols(mod); | |
3630 | if (err < 0) | |
3631 | goto out; | |
3632 | ||
3633 | /* This relies on module_mutex for list integrity. */ | |
3634 | module_bug_finalize(info->hdr, info->sechdrs, mod); | |
3635 | ||
3636 | module_enable_ro(mod, false); | |
3637 | module_enable_nx(mod); | |
3638 | module_enable_x(mod); | |
3639 | ||
3640 | /* Mark state as coming so strong_try_module_get() ignores us, | |
3641 | * but kallsyms etc. can see us. */ | |
3642 | mod->state = MODULE_STATE_COMING; | |
3643 | mutex_unlock(&module_mutex); | |
3644 | ||
3645 | return 0; | |
3646 | ||
3647 | out: | |
3648 | mutex_unlock(&module_mutex); | |
3649 | return err; | |
3650 | } | |
3651 | ||
3652 | static int prepare_coming_module(struct module *mod) | |
3653 | { | |
3654 | int err; | |
3655 | ||
3656 | ftrace_module_enable(mod); | |
3657 | err = klp_module_coming(mod); | |
3658 | if (err) | |
3659 | return err; | |
3660 | ||
3661 | blocking_notifier_call_chain(&module_notify_list, | |
3662 | MODULE_STATE_COMING, mod); | |
3663 | return 0; | |
3664 | } | |
3665 | ||
3666 | static int unknown_module_param_cb(char *param, char *val, const char *modname, | |
3667 | void *arg) | |
3668 | { | |
3669 | struct module *mod = arg; | |
3670 | int ret; | |
3671 | ||
3672 | if (strcmp(param, "async_probe") == 0) { | |
3673 | mod->async_probe_requested = true; | |
3674 | return 0; | |
3675 | } | |
3676 | ||
3677 | /* Check for magic 'dyndbg' arg */ | |
3678 | ret = ddebug_dyndbg_module_param_cb(param, val, modname); | |
3679 | if (ret != 0) | |
3680 | pr_warn("%s: unknown parameter '%s' ignored\n", modname, param); | |
3681 | return 0; | |
3682 | } | |
3683 | ||
3684 | /* Allocate and load the module: note that size of section 0 is always | |
3685 | zero, and we rely on this for optional sections. */ | |
3686 | static int load_module(struct load_info *info, const char __user *uargs, | |
3687 | int flags) | |
3688 | { | |
3689 | struct module *mod; | |
3690 | long err; | |
3691 | char *after_dashes; | |
3692 | ||
3693 | err = module_sig_check(info, flags); | |
3694 | if (err) | |
3695 | goto free_copy; | |
3696 | ||
3697 | err = elf_header_check(info); | |
3698 | if (err) | |
3699 | goto free_copy; | |
3700 | ||
3701 | /* Figure out module layout, and allocate all the memory. */ | |
3702 | mod = layout_and_allocate(info, flags); | |
3703 | if (IS_ERR(mod)) { | |
3704 | err = PTR_ERR(mod); | |
3705 | goto free_copy; | |
3706 | } | |
3707 | ||
3708 | audit_log_kern_module(mod->name); | |
3709 | ||
3710 | /* Reserve our place in the list. */ | |
3711 | err = add_unformed_module(mod); | |
3712 | if (err) | |
3713 | goto free_module; | |
3714 | ||
3715 | #ifdef CONFIG_MODULE_SIG | |
3716 | mod->sig_ok = info->sig_ok; | |
3717 | if (!mod->sig_ok) { | |
3718 | pr_notice_once("%s: module verification failed: signature " | |
3719 | "and/or required key missing - tainting " | |
3720 | "kernel\n", mod->name); | |
3721 | add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK); | |
3722 | } | |
3723 | #endif | |
3724 | ||
3725 | /* To avoid stressing percpu allocator, do this once we're unique. */ | |
3726 | err = percpu_modalloc(mod, info); | |
3727 | if (err) | |
3728 | goto unlink_mod; | |
3729 | ||
3730 | /* Now module is in final location, initialize linked lists, etc. */ | |
3731 | err = module_unload_init(mod); | |
3732 | if (err) | |
3733 | goto unlink_mod; | |
3734 | ||
3735 | init_param_lock(mod); | |
3736 | ||
3737 | /* Now we've got everything in the final locations, we can | |
3738 | * find optional sections. */ | |
3739 | err = find_module_sections(mod, info); | |
3740 | if (err) | |
3741 | goto free_unload; | |
3742 | ||
3743 | err = check_module_license_and_versions(mod); | |
3744 | if (err) | |
3745 | goto free_unload; | |
3746 | ||
3747 | /* Set up MODINFO_ATTR fields */ | |
3748 | setup_modinfo(mod, info); | |
3749 | ||
3750 | /* Fix up syms, so that st_value is a pointer to location. */ | |
3751 | err = simplify_symbols(mod, info); | |
3752 | if (err < 0) | |
3753 | goto free_modinfo; | |
3754 | ||
3755 | err = apply_relocations(mod, info); | |
3756 | if (err < 0) | |
3757 | goto free_modinfo; | |
3758 | ||
3759 | err = post_relocation(mod, info); | |
3760 | if (err < 0) | |
3761 | goto free_modinfo; | |
3762 | ||
3763 | flush_module_icache(mod); | |
3764 | ||
3765 | /* Now copy in args */ | |
3766 | mod->args = strndup_user(uargs, ~0UL >> 1); | |
3767 | if (IS_ERR(mod->args)) { | |
3768 | err = PTR_ERR(mod->args); | |
3769 | goto free_arch_cleanup; | |
3770 | } | |
3771 | ||
3772 | dynamic_debug_setup(mod, info->debug, info->num_debug); | |
3773 | ||
3774 | /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */ | |
3775 | ftrace_module_init(mod); | |
3776 | ||
3777 | /* Finally it's fully formed, ready to start executing. */ | |
3778 | err = complete_formation(mod, info); | |
3779 | if (err) | |
3780 | goto ddebug_cleanup; | |
3781 | ||
3782 | err = prepare_coming_module(mod); | |
3783 | if (err) | |
3784 | goto bug_cleanup; | |
3785 | ||
3786 | /* Module is ready to execute: parsing args may do that. */ | |
3787 | after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, | |
3788 | -32768, 32767, mod, | |
3789 | unknown_module_param_cb); | |
3790 | if (IS_ERR(after_dashes)) { | |
3791 | err = PTR_ERR(after_dashes); | |
3792 | goto coming_cleanup; | |
3793 | } else if (after_dashes) { | |
3794 | pr_warn("%s: parameters '%s' after `--' ignored\n", | |
3795 | mod->name, after_dashes); | |
3796 | } | |
3797 | ||
3798 | /* Link in to sysfs. */ | |
3799 | err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp); | |
3800 | if (err < 0) | |
3801 | goto coming_cleanup; | |
3802 | ||
3803 | if (is_livepatch_module(mod)) { | |
3804 | err = copy_module_elf(mod, info); | |
3805 | if (err < 0) | |
3806 | goto sysfs_cleanup; | |
3807 | } | |
3808 | ||
3809 | /* Get rid of temporary copy. */ | |
3810 | free_copy(info); | |
3811 | ||
3812 | /* Done! */ | |
3813 | trace_module_load(mod); | |
3814 | ||
3815 | return do_init_module(mod); | |
3816 | ||
3817 | sysfs_cleanup: | |
3818 | mod_sysfs_teardown(mod); | |
3819 | coming_cleanup: | |
3820 | mod->state = MODULE_STATE_GOING; | |
3821 | destroy_params(mod->kp, mod->num_kp); | |
3822 | blocking_notifier_call_chain(&module_notify_list, | |
3823 | MODULE_STATE_GOING, mod); | |
3824 | klp_module_going(mod); | |
3825 | bug_cleanup: | |
3826 | /* module_bug_cleanup needs module_mutex protection */ | |
3827 | mutex_lock(&module_mutex); | |
3828 | module_bug_cleanup(mod); | |
3829 | mutex_unlock(&module_mutex); | |
3830 | ||
3831 | /* we can't deallocate the module until we clear memory protection */ | |
3832 | module_disable_ro(mod); | |
3833 | module_disable_nx(mod); | |
3834 | ||
3835 | ddebug_cleanup: | |
3836 | dynamic_debug_remove(mod, info->debug); | |
3837 | synchronize_sched(); | |
3838 | kfree(mod->args); | |
3839 | free_arch_cleanup: | |
3840 | module_arch_cleanup(mod); | |
3841 | free_modinfo: | |
3842 | free_modinfo(mod); | |
3843 | free_unload: | |
3844 | module_unload_free(mod); | |
3845 | unlink_mod: | |
3846 | mutex_lock(&module_mutex); | |
3847 | /* Unlink carefully: kallsyms could be walking list. */ | |
3848 | list_del_rcu(&mod->list); | |
3849 | mod_tree_remove(mod); | |
3850 | wake_up_all(&module_wq); | |
3851 | /* Wait for RCU-sched synchronizing before releasing mod->list. */ | |
3852 | synchronize_sched(); | |
3853 | mutex_unlock(&module_mutex); | |
3854 | free_module: | |
3855 | /* | |
3856 | * Ftrace needs to clean up what it initialized. | |
3857 | * This does nothing if ftrace_module_init() wasn't called, | |
3858 | * but it must be called outside of module_mutex. | |
3859 | */ | |
3860 | ftrace_release_mod(mod); | |
3861 | /* Free lock-classes; relies on the preceding sync_rcu() */ | |
3862 | lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); | |
3863 | ||
3864 | module_deallocate(mod, info); | |
3865 | free_copy: | |
3866 | free_copy(info); | |
3867 | return err; | |
3868 | } | |
3869 | ||
3870 | SYSCALL_DEFINE3(init_module, void __user *, umod, | |
3871 | unsigned long, len, const char __user *, uargs) | |
3872 | { | |
3873 | int err; | |
3874 | struct load_info info = { }; | |
3875 | ||
3876 | err = may_init_module(); | |
3877 | if (err) | |
3878 | return err; | |
3879 | ||
3880 | pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n", | |
3881 | umod, len, uargs); | |
3882 | ||
3883 | err = copy_module_from_user(umod, len, &info); | |
3884 | if (err) | |
3885 | return err; | |
3886 | ||
3887 | return load_module(&info, uargs, 0); | |
3888 | } | |
3889 | ||
3890 | SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) | |
3891 | { | |
3892 | struct load_info info = { }; | |
3893 | loff_t size; | |
3894 | void *hdr; | |
3895 | int err; | |
3896 | ||
3897 | err = may_init_module(); | |
3898 | if (err) | |
3899 | return err; | |
3900 | ||
3901 | pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags); | |
3902 | ||
3903 | if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS | |
3904 | |MODULE_INIT_IGNORE_VERMAGIC)) | |
3905 | return -EINVAL; | |
3906 | ||
3907 | err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX, | |
3908 | READING_MODULE); | |
3909 | if (err) | |
3910 | return err; | |
3911 | info.hdr = hdr; | |
3912 | info.len = size; | |
3913 | ||
3914 | return load_module(&info, uargs, flags); | |
3915 | } | |
3916 | ||
3917 | static inline int within(unsigned long addr, void *start, unsigned long size) | |
3918 | { | |
3919 | return ((void *)addr >= start && (void *)addr < start + size); | |
3920 | } | |
3921 | ||
3922 | #ifdef CONFIG_KALLSYMS | |
3923 | /* | |
3924 | * This ignores the intensely annoying "mapping symbols" found | |
3925 | * in ARM ELF files: $a, $t and $d. | |
3926 | */ | |
3927 | static inline int is_arm_mapping_symbol(const char *str) | |
3928 | { | |
3929 | if (str[0] == '.' && str[1] == 'L') | |
3930 | return true; | |
3931 | return str[0] == '$' && strchr("axtd", str[1]) | |
3932 | && (str[2] == '\0' || str[2] == '.'); | |
3933 | } | |
3934 | ||
3935 | static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum) | |
3936 | { | |
3937 | return kallsyms->strtab + kallsyms->symtab[symnum].st_name; | |
3938 | } | |
3939 | ||
3940 | static const char *get_ksymbol(struct module *mod, | |
3941 | unsigned long addr, | |
3942 | unsigned long *size, | |
3943 | unsigned long *offset) | |
3944 | { | |
3945 | unsigned int i, best = 0; | |
3946 | unsigned long nextval; | |
3947 | struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); | |
3948 | ||
3949 | /* At worse, next value is at end of module */ | |
3950 | if (within_module_init(addr, mod)) | |
3951 | nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size; | |
3952 | else | |
3953 | nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size; | |
3954 | ||
3955 | /* Scan for closest preceding symbol, and next symbol. (ELF | |
3956 | starts real symbols at 1). */ | |
3957 | for (i = 1; i < kallsyms->num_symtab; i++) { | |
3958 | if (kallsyms->symtab[i].st_shndx == SHN_UNDEF) | |
3959 | continue; | |
3960 | ||
3961 | /* We ignore unnamed symbols: they're uninformative | |
3962 | * and inserted at a whim. */ | |
3963 | if (*symname(kallsyms, i) == '\0' | |
3964 | || is_arm_mapping_symbol(symname(kallsyms, i))) | |
3965 | continue; | |
3966 | ||
3967 | if (kallsyms->symtab[i].st_value <= addr | |
3968 | && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value) | |
3969 | best = i; | |
3970 | if (kallsyms->symtab[i].st_value > addr | |
3971 | && kallsyms->symtab[i].st_value < nextval) | |
3972 | nextval = kallsyms->symtab[i].st_value; | |
3973 | } | |
3974 | ||
3975 | if (!best) | |
3976 | return NULL; | |
3977 | ||
3978 | if (size) | |
3979 | *size = nextval - kallsyms->symtab[best].st_value; | |
3980 | if (offset) | |
3981 | *offset = addr - kallsyms->symtab[best].st_value; | |
3982 | return symname(kallsyms, best); | |
3983 | } | |
3984 | ||
3985 | /* For kallsyms to ask for address resolution. NULL means not found. Careful | |
3986 | * not to lock to avoid deadlock on oopses, simply disable preemption. */ | |
3987 | const char *module_address_lookup(unsigned long addr, | |
3988 | unsigned long *size, | |
3989 | unsigned long *offset, | |
3990 | char **modname, | |
3991 | char *namebuf) | |
3992 | { | |
3993 | const char *ret = NULL; | |
3994 | struct module *mod; | |
3995 | ||
3996 | preempt_disable(); | |
3997 | mod = __module_address(addr); | |
3998 | if (mod) { | |
3999 | if (modname) | |
4000 | *modname = mod->name; | |
4001 | ret = get_ksymbol(mod, addr, size, offset); | |
4002 | } | |
4003 | /* Make a copy in here where it's safe */ | |
4004 | if (ret) { | |
4005 | strncpy(namebuf, ret, KSYM_NAME_LEN - 1); | |
4006 | ret = namebuf; | |
4007 | } | |
4008 | preempt_enable(); | |
4009 | ||
4010 | return ret; | |
4011 | } | |
4012 | ||
4013 | int lookup_module_symbol_name(unsigned long addr, char *symname) | |
4014 | { | |
4015 | struct module *mod; | |
4016 | ||
4017 | preempt_disable(); | |
4018 | list_for_each_entry_rcu(mod, &modules, list) { | |
4019 | if (mod->state == MODULE_STATE_UNFORMED) | |
4020 | continue; | |
4021 | if (within_module(addr, mod)) { | |
4022 | const char *sym; | |
4023 | ||
4024 | sym = get_ksymbol(mod, addr, NULL, NULL); | |
4025 | if (!sym) | |
4026 | goto out; | |
4027 | strlcpy(symname, sym, KSYM_NAME_LEN); | |
4028 | preempt_enable(); | |
4029 | return 0; | |
4030 | } | |
4031 | } | |
4032 | out: | |
4033 | preempt_enable(); | |
4034 | return -ERANGE; | |
4035 | } | |
4036 | ||
4037 | int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, | |
4038 | unsigned long *offset, char *modname, char *name) | |
4039 | { | |
4040 | struct module *mod; | |
4041 | ||
4042 | preempt_disable(); | |
4043 | list_for_each_entry_rcu(mod, &modules, list) { | |
4044 | if (mod->state == MODULE_STATE_UNFORMED) | |
4045 | continue; | |
4046 | if (within_module(addr, mod)) { | |
4047 | const char *sym; | |
4048 | ||
4049 | sym = get_ksymbol(mod, addr, size, offset); | |
4050 | if (!sym) | |
4051 | goto out; | |
4052 | if (modname) | |
4053 | strlcpy(modname, mod->name, MODULE_NAME_LEN); | |
4054 | if (name) | |
4055 | strlcpy(name, sym, KSYM_NAME_LEN); | |
4056 | preempt_enable(); | |
4057 | return 0; | |
4058 | } | |
4059 | } | |
4060 | out: | |
4061 | preempt_enable(); | |
4062 | return -ERANGE; | |
4063 | } | |
4064 | ||
4065 | int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, | |
4066 | char *name, char *module_name, int *exported) | |
4067 | { | |
4068 | struct module *mod; | |
4069 | ||
4070 | preempt_disable(); | |
4071 | list_for_each_entry_rcu(mod, &modules, list) { | |
4072 | struct mod_kallsyms *kallsyms; | |
4073 | ||
4074 | if (mod->state == MODULE_STATE_UNFORMED) | |
4075 | continue; | |
4076 | kallsyms = rcu_dereference_sched(mod->kallsyms); | |
4077 | if (symnum < kallsyms->num_symtab) { | |
4078 | *value = kallsyms->symtab[symnum].st_value; | |
4079 | *type = kallsyms->symtab[symnum].st_info; | |
4080 | strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN); | |
4081 | strlcpy(module_name, mod->name, MODULE_NAME_LEN); | |
4082 | *exported = is_exported(name, *value, mod); | |
4083 | preempt_enable(); | |
4084 | return 0; | |
4085 | } | |
4086 | symnum -= kallsyms->num_symtab; | |
4087 | } | |
4088 | preempt_enable(); | |
4089 | return -ERANGE; | |
4090 | } | |
4091 | ||
4092 | static unsigned long mod_find_symname(struct module *mod, const char *name) | |
4093 | { | |
4094 | unsigned int i; | |
4095 | struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); | |
4096 | ||
4097 | for (i = 0; i < kallsyms->num_symtab; i++) | |
4098 | if (strcmp(name, symname(kallsyms, i)) == 0 && | |
4099 | kallsyms->symtab[i].st_shndx != SHN_UNDEF) | |
4100 | return kallsyms->symtab[i].st_value; | |
4101 | return 0; | |
4102 | } | |
4103 | ||
4104 | /* Look for this name: can be of form module:name. */ | |
4105 | unsigned long module_kallsyms_lookup_name(const char *name) | |
4106 | { | |
4107 | struct module *mod; | |
4108 | char *colon; | |
4109 | unsigned long ret = 0; | |
4110 | ||
4111 | /* Don't lock: we're in enough trouble already. */ | |
4112 | preempt_disable(); | |
4113 | if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) { | |
4114 | if ((mod = find_module_all(name, colon - name, false)) != NULL) | |
4115 | ret = mod_find_symname(mod, colon+1); | |
4116 | } else { | |
4117 | list_for_each_entry_rcu(mod, &modules, list) { | |
4118 | if (mod->state == MODULE_STATE_UNFORMED) | |
4119 | continue; | |
4120 | if ((ret = mod_find_symname(mod, name)) != 0) | |
4121 | break; | |
4122 | } | |
4123 | } | |
4124 | preempt_enable(); | |
4125 | return ret; | |
4126 | } | |
4127 | ||
4128 | int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, | |
4129 | struct module *, unsigned long), | |
4130 | void *data) | |
4131 | { | |
4132 | struct module *mod; | |
4133 | unsigned int i; | |
4134 | int ret; | |
4135 | ||
4136 | module_assert_mutex(); | |
4137 | ||
4138 | list_for_each_entry(mod, &modules, list) { | |
4139 | /* We hold module_mutex: no need for rcu_dereference_sched */ | |
4140 | struct mod_kallsyms *kallsyms = mod->kallsyms; | |
4141 | ||
4142 | if (mod->state == MODULE_STATE_UNFORMED) | |
4143 | continue; | |
4144 | for (i = 0; i < kallsyms->num_symtab; i++) { | |
4145 | ||
4146 | if (kallsyms->symtab[i].st_shndx == SHN_UNDEF) | |
4147 | continue; | |
4148 | ||
4149 | ret = fn(data, symname(kallsyms, i), | |
4150 | mod, kallsyms->symtab[i].st_value); | |
4151 | if (ret != 0) | |
4152 | return ret; | |
4153 | } | |
4154 | } | |
4155 | return 0; | |
4156 | } | |
4157 | #endif /* CONFIG_KALLSYMS */ | |
4158 | ||
4159 | /* Maximum number of characters written by module_flags() */ | |
4160 | #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) | |
4161 | ||
4162 | /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */ | |
4163 | static char *module_flags(struct module *mod, char *buf) | |
4164 | { | |
4165 | int bx = 0; | |
4166 | ||
4167 | BUG_ON(mod->state == MODULE_STATE_UNFORMED); | |
4168 | if (mod->taints || | |
4169 | mod->state == MODULE_STATE_GOING || | |
4170 | mod->state == MODULE_STATE_COMING) { | |
4171 | buf[bx++] = '('; | |
4172 | bx += module_flags_taint(mod, buf + bx); | |
4173 | /* Show a - for module-is-being-unloaded */ | |
4174 | if (mod->state == MODULE_STATE_GOING) | |
4175 | buf[bx++] = '-'; | |
4176 | /* Show a + for module-is-being-loaded */ | |
4177 | if (mod->state == MODULE_STATE_COMING) | |
4178 | buf[bx++] = '+'; | |
4179 | buf[bx++] = ')'; | |
4180 | } | |
4181 | buf[bx] = '\0'; | |
4182 | ||
4183 | return buf; | |
4184 | } | |
4185 | ||
4186 | #ifdef CONFIG_PROC_FS | |
4187 | /* Called by the /proc file system to return a list of modules. */ | |
4188 | static void *m_start(struct seq_file *m, loff_t *pos) | |
4189 | { | |
4190 | mutex_lock(&module_mutex); | |
4191 | return seq_list_start(&modules, *pos); | |
4192 | } | |
4193 | ||
4194 | static void *m_next(struct seq_file *m, void *p, loff_t *pos) | |
4195 | { | |
4196 | return seq_list_next(p, &modules, pos); | |
4197 | } | |
4198 | ||
4199 | static void m_stop(struct seq_file *m, void *p) | |
4200 | { | |
4201 | mutex_unlock(&module_mutex); | |
4202 | } | |
4203 | ||
4204 | static int m_show(struct seq_file *m, void *p) | |
4205 | { | |
4206 | struct module *mod = list_entry(p, struct module, list); | |
4207 | char buf[MODULE_FLAGS_BUF_SIZE]; | |
4208 | void *value; | |
4209 | ||
4210 | /* We always ignore unformed modules. */ | |
4211 | if (mod->state == MODULE_STATE_UNFORMED) | |
4212 | return 0; | |
4213 | ||
4214 | seq_printf(m, "%s %u", | |
4215 | mod->name, mod->init_layout.size + mod->core_layout.size); | |
4216 | print_unload_info(m, mod); | |
4217 | ||
4218 | /* Informative for users. */ | |
4219 | seq_printf(m, " %s", | |
4220 | mod->state == MODULE_STATE_GOING ? "Unloading" : | |
4221 | mod->state == MODULE_STATE_COMING ? "Loading" : | |
4222 | "Live"); | |
4223 | /* Used by oprofile and other similar tools. */ | |
4224 | value = m->private ? NULL : mod->core_layout.base; | |
4225 | seq_printf(m, " 0x%px", value); | |
4226 | ||
4227 | /* Taints info */ | |
4228 | if (mod->taints) | |
4229 | seq_printf(m, " %s", module_flags(mod, buf)); | |
4230 | ||
4231 | seq_puts(m, "\n"); | |
4232 | return 0; | |
4233 | } | |
4234 | ||
4235 | /* Format: modulename size refcount deps address | |
4236 | ||
4237 | Where refcount is a number or -, and deps is a comma-separated list | |
4238 | of depends or -. | |
4239 | */ | |
4240 | static const struct seq_operations modules_op = { | |
4241 | .start = m_start, | |
4242 | .next = m_next, | |
4243 | .stop = m_stop, | |
4244 | .show = m_show | |
4245 | }; | |
4246 | ||
4247 | /* | |
4248 | * This also sets the "private" pointer to non-NULL if the | |
4249 | * kernel pointers should be hidden (so you can just test | |
4250 | * "m->private" to see if you should keep the values private). | |
4251 | * | |
4252 | * We use the same logic as for /proc/kallsyms. | |
4253 | */ | |
4254 | static int modules_open(struct inode *inode, struct file *file) | |
4255 | { | |
4256 | int err = seq_open(file, &modules_op); | |
4257 | ||
4258 | if (!err) { | |
4259 | struct seq_file *m = file->private_data; | |
4260 | m->private = kallsyms_show_value() ? NULL : (void *)8ul; | |
4261 | } | |
4262 | ||
4263 | return err; | |
4264 | } | |
4265 | ||
4266 | static const struct file_operations proc_modules_operations = { | |
4267 | .open = modules_open, | |
4268 | .read = seq_read, | |
4269 | .llseek = seq_lseek, | |
4270 | .release = seq_release, | |
4271 | }; | |
4272 | ||
4273 | static int __init proc_modules_init(void) | |
4274 | { | |
4275 | proc_create("modules", 0, NULL, &proc_modules_operations); | |
4276 | return 0; | |
4277 | } | |
4278 | module_init(proc_modules_init); | |
4279 | #endif | |
4280 | ||
4281 | /* Given an address, look for it in the module exception tables. */ | |
4282 | const struct exception_table_entry *search_module_extables(unsigned long addr) | |
4283 | { | |
4284 | const struct exception_table_entry *e = NULL; | |
4285 | struct module *mod; | |
4286 | ||
4287 | preempt_disable(); | |
4288 | mod = __module_address(addr); | |
4289 | if (!mod) | |
4290 | goto out; | |
4291 | ||
4292 | if (!mod->num_exentries) | |
4293 | goto out; | |
4294 | ||
4295 | e = search_extable(mod->extable, | |
4296 | mod->num_exentries, | |
4297 | addr); | |
4298 | out: | |
4299 | preempt_enable(); | |
4300 | ||
4301 | /* | |
4302 | * Now, if we found one, we are running inside it now, hence | |
4303 | * we cannot unload the module, hence no refcnt needed. | |
4304 | */ | |
4305 | return e; | |
4306 | } | |
4307 | ||
4308 | /* | |
4309 | * is_module_address - is this address inside a module? | |
4310 | * @addr: the address to check. | |
4311 | * | |
4312 | * See is_module_text_address() if you simply want to see if the address | |
4313 | * is code (not data). | |
4314 | */ | |
4315 | bool is_module_address(unsigned long addr) | |
4316 | { | |
4317 | bool ret; | |
4318 | ||
4319 | preempt_disable(); | |
4320 | ret = __module_address(addr) != NULL; | |
4321 | preempt_enable(); | |
4322 | ||
4323 | return ret; | |
4324 | } | |
4325 | ||
4326 | /* | |
4327 | * __module_address - get the module which contains an address. | |
4328 | * @addr: the address. | |
4329 | * | |
4330 | * Must be called with preempt disabled or module mutex held so that | |
4331 | * module doesn't get freed during this. | |
4332 | */ | |
4333 | struct module *__module_address(unsigned long addr) | |
4334 | { | |
4335 | struct module *mod; | |
4336 | ||
4337 | if (addr < module_addr_min || addr > module_addr_max) | |
4338 | return NULL; | |
4339 | ||
4340 | module_assert_mutex_or_preempt(); | |
4341 | ||
4342 | mod = mod_find(addr); | |
4343 | if (mod) { | |
4344 | BUG_ON(!within_module(addr, mod)); | |
4345 | if (mod->state == MODULE_STATE_UNFORMED) | |
4346 | mod = NULL; | |
4347 | } | |
4348 | return mod; | |
4349 | } | |
4350 | EXPORT_SYMBOL_GPL(__module_address); | |
4351 | ||
4352 | /* | |
4353 | * is_module_text_address - is this address inside module code? | |
4354 | * @addr: the address to check. | |
4355 | * | |
4356 | * See is_module_address() if you simply want to see if the address is | |
4357 | * anywhere in a module. See kernel_text_address() for testing if an | |
4358 | * address corresponds to kernel or module code. | |
4359 | */ | |
4360 | bool is_module_text_address(unsigned long addr) | |
4361 | { | |
4362 | bool ret; | |
4363 | ||
4364 | preempt_disable(); | |
4365 | ret = __module_text_address(addr) != NULL; | |
4366 | preempt_enable(); | |
4367 | ||
4368 | return ret; | |
4369 | } | |
4370 | ||
4371 | /* | |
4372 | * __module_text_address - get the module whose code contains an address. | |
4373 | * @addr: the address. | |
4374 | * | |
4375 | * Must be called with preempt disabled or module mutex held so that | |
4376 | * module doesn't get freed during this. | |
4377 | */ | |
4378 | struct module *__module_text_address(unsigned long addr) | |
4379 | { | |
4380 | struct module *mod = __module_address(addr); | |
4381 | if (mod) { | |
4382 | /* Make sure it's within the text section. */ | |
4383 | if (!within(addr, mod->init_layout.base, mod->init_layout.text_size) | |
4384 | && !within(addr, mod->core_layout.base, mod->core_layout.text_size)) | |
4385 | mod = NULL; | |
4386 | } | |
4387 | return mod; | |
4388 | } | |
4389 | EXPORT_SYMBOL_GPL(__module_text_address); | |
4390 | ||
4391 | /* Don't grab lock, we're oopsing. */ | |
4392 | void print_modules(void) | |
4393 | { | |
4394 | struct module *mod; | |
4395 | char buf[MODULE_FLAGS_BUF_SIZE]; | |
4396 | ||
4397 | printk(KERN_DEFAULT "Modules linked in:"); | |
4398 | /* Most callers should already have preempt disabled, but make sure */ | |
4399 | preempt_disable(); | |
4400 | list_for_each_entry_rcu(mod, &modules, list) { | |
4401 | if (mod->state == MODULE_STATE_UNFORMED) | |
4402 | continue; | |
4403 | pr_cont(" %s%s", mod->name, module_flags(mod, buf)); | |
4404 | } | |
4405 | preempt_enable(); | |
4406 | if (last_unloaded_module[0]) | |
4407 | pr_cont(" [last unloaded: %s]", last_unloaded_module); | |
4408 | pr_cont("\n"); | |
4409 | } | |
4410 | ||
4411 | #ifdef CONFIG_MODVERSIONS | |
4412 | /* Generate the signature for all relevant module structures here. | |
4413 | * If these change, we don't want to try to parse the module. */ | |
4414 | void module_layout(struct module *mod, | |
4415 | struct modversion_info *ver, | |
4416 | struct kernel_param *kp, | |
4417 | struct kernel_symbol *ks, | |
4418 | struct tracepoint * const *tp) | |
4419 | { | |
4420 | } | |
4421 | EXPORT_SYMBOL(module_layout); | |
4422 | #endif |